Ride vehicle tracking and control system using passive tracking elements

ABSTRACT

A dynamic signal to noise ratio tracking system enables detection and tracking of ride vehicles within the field of view of the tracking system. The tracking system may include an emitter configured to emit electromagnetic radiation within an area, a detector configured to detect electromagnetic radiation reflected back from within the area, and a control unit configured to evaluate signals from the detector and control the ride vehicles or other equipment as a result of this evaluation.

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of U.S. Provisional Application No.62/001,551, filed May 21, 2014, which is incorporated herein byreference in its entirety for all purposes.

BACKGROUND

The present disclosure relates generally to the field of trackingsystems and, more particularly, to methods and equipment used to enabletracking of elements in a variety of contexts through a dynamic signalto noise ratio tracking system.

Tracking systems have been widely used to track motion, position,orientation, and distance, among other aspects, of objects in a widevariety of contexts. Such existing tracking systems generally include anemitter that emits electromagnetic energy and a detector configured todetect the electromagnetic energy, sometimes after it has been reflectedoff an object. It is now recognized that traditional tracking systemshave certain disadvantages and that improved tracking systems aredesired for use in a variety of contexts, including amusement parkattractions, workplace monitoring, sports, fireworks displays, factoryfloor management, robotics, security systems, parking, andtransportation, among others.

BRIEF DESCRIPTION

In accordance with an embodiment of the present disclosure, an amusementpark ride system includes: a ride vehicle positioned on a ride path andconfigured to move along the ride path; a plurality of retro-reflectivemarkers positioned on the ride vehicle, along the ride path, or both; anemission subsystem configured to emit electromagnetic radiation towardthe plurality of retro-reflective markers; a detection subsystemconfigured to detect a pattern of retro-reflection of theelectromagnetic radiation from the plurality of retro-reflective markerswhile filtering electromagnetic radiation that is not retro-reflected;and a control system communicatively coupled to the detection subsystemand having processing circuitry configured to: monitor the pattern ofretro-reflection of the electromagnetic radiation from the plurality ofretro-reflective markers for changes; and track movement of the ridevehicle in space and time based on changes in the pattern ofretro-reflected electromagnetic radiation detected by the detectionsubsystem.

In accordance with another embodiment of the present disclosure, anamusement park ride system includes a ride vehicle positioned on a ridepath and configured to move along the ride path; a plurality ofretro-reflective markers positioned on the ride vehicle, along the ridepath, or both; an emission subsystem configured to emit electromagneticradiation toward the plurality of retro-reflective markers; a detectionsubsystem configured to detect a pattern of retro-reflection of theelectromagnetic radiation from the plurality of retro-reflective markerswhile filtering electromagnetic radiation that is not retro-reflected;and a control system communicatively coupled to the detection subsystemand having processing circuitry configured to: monitor the pattern ofretro-reflection of the electromagnetic radiation from the plurality ofretro-reflective markers for changes; and track movement of the ridevehicle in space and time based on changes in the pattern ofretro-reflected electromagnetic radiation detected by the detectionsubsystem.

In accordance with a further embodiment of the present disclosure, anamusement park system includes a control system comprising processingcircuitry configured to receive data indicative of retro-reflection ofelectromagnetic radiation by a plurality of retro-reflective markers,wherein the control system is configured to monitor the retro-reflectedelectromagnetic radiation to track a location and movement of a ridevehicle relative to a ride vehicle path based solely on changes in theretro-reflected electromagnetic radiation.

DRAWINGS

These and other features, aspects, and advantages of the presentdisclosure will become better understood when the following detaileddescription is read with reference to the accompanying drawings in whichlike characters represent like parts throughout the drawings, wherein:

FIG. 1 is a schematic diagram of a tracking system utilizing a dynamicsignal to noise ratio device to track objects, in accordance with anembodiment of the present disclosure;

FIG. 2 is a schematic diagram of another tracking system utilizing adynamic signal to noise ratio device to track objects, in accordancewith an embodiment of the present disclosure;

FIG. 3 is a schematic view of the tracking system of FIG. 1 tracking aretro-reflective marker on a person, in accordance with an embodiment ofthe present disclosure;

FIG. 4 is a schematic representation of an analysis performed by thetracking system of FIG. 1 in which position and movement of a person orobject is tracked in space and time, in accordance with an embodiment ofthe present disclosure;

FIG. 5 is an overhead view of a room with a grid pattern ofretro-reflective markers for tracking a position of people in the roomvia the tracking system of FIG. 1, in accordance with an embodiment ofthe present disclosure;

FIG. 6 is an elevational view of the tracking system of FIG. 1 trackinga person without tracking retro-reflective marker movement and withouttracking retro-reflective marker occlusion, in accordance with anembodiment of the present disclosure;

FIG. 7 is an elevational view of a room with a grid pattern ofretro-reflective markers disposed on a wall and a floor of the room fortracking a position of people and objects in the room via the trackingsystem of FIG. 1, in accordance with an embodiment of the presentdisclosure;

FIG. 8 illustrates cross-sections of retro-reflective markers havingdifferent coatings to enable different wavelengths of electromagneticradiation to be reflected back toward the detector of the trackingsystem of FIG. 1, in accordance with an embodiment of the presentdisclosure;

FIGS. 9A-9C depict the manner in which an object may be tracked in threespatial dimensions by the tracking system of FIG. 1, in accordance withan embodiment of the present disclosure;

FIG. 10 is a flow diagram illustrating an embodiment of a method oftracking reflection and controlling amusement park elements based on thetracked reflection using the tracking system of FIG. 1, in accordancewith an embodiment of the present disclosure;

FIG. 11 is a flow diagram illustrating an embodiment of a method oftracking retro-reflection to evaluate information relating to machinesand people, and controlling amusement park elements based on theevaluated information using the tracking system of FIG. 1, in accordancewith an embodiment of the present disclosure;

FIG. 12 is a schematic view of an embodiment of an amusement parkattraction and control system configured to track attraction equipmentin relation to other machines or people, in accordance with anembodiment of the present disclosure;

FIG. 13 is an overhead schematic view of a room with a grid pattern ofretro-reflective markers for tracking a position of people and machinesin the room via the tracking system of FIG. 1, in accordance with anembodiment of the present disclosure;

FIG. 14 is an overhead schematic view of a room with a grid pattern ofretro-reflective markers for tracking a position of people relative to aboundary applied to machines via the tracking system of FIG. 1, inaccordance with an embodiment of the present disclosure;

FIG. 15 is a process flow diagram of a method for controlling operationof the machines in the room of FIG. 13 via feedback from the trackingsystem, in accordance with an embodiment of the present disclosure;

FIG. 16 is an overhead schematic view of machines being controlled tomove through a crowd of people based on feedback received from thetracking system of FIG. 1, in accordance with an embodiment of thepresent disclosure;

FIG. 17 is an overhead schematic view of machines being controlled totarget groups of people based on feedback received from the trackingsystem of FIG. 1, in accordance with an embodiment of the presentdisclosure;

FIG. 18 is an illustration of an animated figure with retro-reflectivemarkers disposed thereon for use with the tracking system of FIG. 1, inaccordance with an embodiment of the present disclosure;

FIG. 19 is an overhead view of an amusement park having an unmannedaerial system (UAS) configured to direct unmanned aerial vehicles (UAVs)through the park using the tracking system of FIG. 1, in accordance withan embodiment of the present disclosure;

FIG. 20 is a bottom view of a UAV having interactive and positioncontrol components, in accordance with an embodiment of the presentdisclosure;

FIG. 21 is a front view of a UAV having the tracking system of FIG. 1integrated onto its body, in accordance with an embodiment of thepresent disclosure;

FIG. 22 is an overhead schematic view of a series of amusement park ridevehicles with markers used to convey embedded data to the trackingsystem of FIG. 1, in accordance with an embodiment of the presentdisclosure;

FIG. 23 is a perspective view of two orthogonally positioned trackingsystems of FIG. 1 detecting a three dimensional location of an amusementattraction vehicle, in accordance with an embodiment of the presentdisclosure;

FIG. 24 is a perspective view of an amusement park ride vehicletraveling along a constrained path having retro-reflective markers onthe path to enable the tracking system of FIG. 1 to evaluate theperformance of the ride vehicle, in accordance with an embodiment of thepresent disclosure;

FIG. 25 is an overhead view of a portion of the constrained path of FIG.24 and schematically illustrating occlusion and non-occlusion of theretro-reflective markers on the path by the ride vehicles travellingalong the path, in accordance with an embodiment of the presentdisclosure;

FIG. 26 is an overhead view of an unconstrained path havingretro-reflective markers positioned at various points along the path toenable the tracking system of FIG. 1 to perform at least a portion ofblock zone control of ride vehicle positions, in accordance with anembodiment of the present disclosure;

FIG. 27 is an elevational view of an embodiment of the unconstrainedpath of FIG. 26 in which the retro-reflective markers on the path andthe tracking system of FIG. 1 are utilized to guide a ride vehicletoward a predetermined destination, in accordance with an embodiment ofthe present disclosure;

FIG. 28 is an overhead view of the path of FIG. 27 and depicting furtherdetails of the manner in which the retro-reflective markers arepositioned to guide the ride vehicle, in accordance with an embodimentof the present disclosure;

FIG. 29 is an overhead view of the path of FIG. 27 and depicting furtherdetails of the manner in which retro-reflective markers may bepositioned in layers to guide the ride vehicle, in accordance with anembodiment of the present disclosure; and

FIG. 30 is an overhead view of another embodiment of the path of FIG. 27and depicting the manner in which the retro-reflective markers may bepositioned to guide the ride vehicle, in accordance with an embodimentof the present disclosure.

DETAILED DESCRIPTION

Generally, tracking systems may use a wide variety of inputs obtainedfrom a surrounding environment to track certain objects. The source ofthe inputs may depend, for instance, on the type of tracking beingperformed and the capabilities of the tracking system. For example,tracking systems may use sensors disposed in an environment to activelygenerate outputs received by a main controller. The controller may thenprocess the generated outputs to determine certain information used fortracking. One example of such tracking may include tracking the motionof an object to which a sensor is fixed. Such a system might alsoutilize one or more devices used to bathe an area in electromagneticradiation, a magnetic field, or the like, where the electromagneticradiation or magnetic field is used as a reference against which thesensor's output is compared by the controller. As may be appreciated,such active systems, if implemented to track a large number of objectsor even people, could be quite expensive to employ andprocessor-intensive for the main controller of the tracking system.

Other tracking systems, such as certain passive tracking systems, mayperform tracking without providing an illumination source or the like.For instance, certain tracking systems may use one or more cameras toobtain outlines or rough skeletal estimates of objects, people, and soforth. However, in situations where background illumination may beintense, such as outside on a hot and sunny day, the accuracy of such asystem may be reduced due to varying degrees of noise received bydetectors of the passive tracking system.

With the foregoing in mind, it is now recognized that traditionaltracking systems have certain disadvantages and that improved trackingsystems are desired for use in a variety of contexts, includingamusement park attractions, workplace monitoring, sports, and securitysystems, among others. For instance, it is presently recognized thatimproved tracking systems may be utilized to enhance operations in avariety of amusement park settings and other entertainment attractions.

In accordance with one aspect of the present disclosure, a dynamicsignal to noise ratio tracking system uses emitted electromagneticradiation and, in some embodiments, retro-reflection, to enabledetection of markers and/or objects within the field of view of thetracking system. The disclosed tracking system may include an emitterconfigured to emit electromagnetic radiation in a field of view, asensing device configured to detect the electromagnetic radiationretro-reflected back from objects within the field of view, and acontroller configured to perform various processing and analysisroutines including interpreting signals from the sensing device andcontrolling automated equipment based on the detected locations of theobjects or markers. The disclosed tracking system may also be configuredto track several different objects at the same time (using the sameemission and detection features). In some embodiments, the trackingsystem tracks a location of retro-reflective markers placed on theobjects to estimate a location of the objects. As used herein,retro-reflective markers are reflective markers designed toretro-reflect electromagnetic radiation approximately back in thedirection from which the electromagnetic radiation was emitted. Morespecifically, retro-reflective markers used in accordance with thepresent disclosure, when illuminated, reflect electromagnetic radiationback toward the source of emission in a narrow cone. In contrast,certain other reflective materials, such as shiny materials, may undergodiffuse reflection where electromagnetic radiation is reflected in manydirections. Further still, mirrors, which also reflect electromagneticradiation, do not typically undergo retro-reflection. Rather, mirrorsundergo specular reflection, where an angle of electromagnetic radiation(e.g., light such as infrared, ultraviolet, visible, or radio waves andso forth) incident onto the mirror is reflected at an equal but oppositeangle (away from the emission source).

Retro-reflective materials used in accordance with the embodiments setforth below can be readily obtained from a number of commercial sources.One example includes retro-reflective tape, which may be fitted to anumber of different objects (e.g., environmental features, clothingitems, toys). Due to the manner in which retro-reflection occurs usingsuch markers in combination with the detectors 16 used in accordancewith the present disclosure, the retro-reflective markers cannot bewashed out by the sun or even in the presence of other emitters thatemit electromagnetic radiation in wavelengths that overlap with thewavelengths of interest. Accordingly, the disclosed tracking system maybe more reliable, especially in an outdoor setting and in the presenceof other electromagnetic emission sources, compared to existing opticaltracking systems.

While the present disclosure is applicable to a number of differentcontexts, presently disclosed embodiments are directed to, among otherthings, various aspects relating to tracking objects and people withinan amusement park, and, in some situations, controlling amusement parkequipment (e.g., automated equipment) based on information obtained fromsuch a dynamic signal to noise ratio tracking system. Indeed, it ispresently recognized that by using the disclosed tracking systems,reliable and efficient amusement park operations may be carried out,even though there are a number of moving objects, guests, employees,sounds, lights, and so forth, in an amusement park, which couldotherwise create high levels of noise for other tracking systems,especially other optical tracking systems that do not useretro-reflective markers in the manner disclosed herein.

In certain aspects of the present disclosure, a control system of theamusement park (e.g., a control system associated with a particular areaof the amusement park, such as a ride) may use information obtained bythe dynamic signal to noise ratio tracking system to monitor andevaluate information relating to people, machines, vehicles (e.g., guestvehicles, service vehicles), and similar features in the area to provideinformation that may be useful in the more efficient operation ofamusement park operations. For example, the information may be used todetermine whether certain automated processes may be triggered orotherwise allowed to proceed. The evaluated information pertaining tovehicles in the amusement park may include, for instance, a location, amovement, a size, or other information relating to automated machines,ride vehicles, and so forth, within certain areas of the amusement park.By way of non-limiting example, the information may be evaluated totrack people and machines to provide enhanced interactivity between thepeople and the machines, to track and control unmanned aerial vehicles,to track and control ride vehicles and any show effects associated withthe ride vehicle, and so forth.

Certain aspects of the present disclosure may be better understood withreference to FIG. 1, which generally illustrates the manner in which adynamic signal to noise ratio tracking system 10 (hereinafter referredto as “tracking system 10”) may be integrated with amusement parkequipment 12 in accordance with present embodiments. As illustrated, thetracking system 10 includes an emitter 14 (which may be all or a part ofan emission subsystem having one or more emission devices and associatedcontrol circuitry) configured to emit one or more wavelengths ofelectromagnetic radiation (e.g., light such as infrared, ultraviolet,visible, or radio waves and so forth) in a general direction. Thetracking system 10 also includes a detector 16 (which may be all or apart of a detection subsystem having one or more sensors, cameras, orthe like, and associated control circuitry) configured to detectelectromagnetic radiation reflected as a result of the emission, asdescribed in further detail below.

To control operations of the emitter 14 and detector 16 (emissionsubsystem and detection subsystem) and perform various signal processingroutines resulting from the emission, reflection, and detection process,the tracking system 10 also includes a control unit 18 communicativelycoupled to the emitter 14 and detector 16. Accordingly, the control unit18 may include one or more processors 20 and one or more memory 22,which may generally referred to herein as “processing circuitry.” By wayof specific but non-limiting example, the one or more processors 20 mayinclude one or more application specific integrated circuits (ASICs),one or more field programmable gate arrays (FPGAs), one or more generalpurpose processors, or any combination thereof. Additionally, the one ormore memory 22 may include volatile memory, such as random access memory(RAM), and/or non-volatile memory, such as read-only memory (ROM),optical drives, hard disc drives, or solid-state drives. In someembodiments, the control unit 18 may form at least a portion of acontrol system configured to coordinate operations of various amusementpark features, including the equipment 12. As described below, such anintegrated system may be referred to as an amusement park attraction andcontrol system.

The tracking system 10 is specifically configured to detect a positionof an illuminated component, such as a retro-reflective marker 24 havinga properly correlated retro-reflective material relative to a grid,pattern, the emission source, stationary or moving environmentalelements, or the like. In some embodiments, the tracking system 10 isdesigned to utilize the relative positioning to identify whether acorrelation exists between one or more such illuminated components and aparticular action to be performed by the amusement park equipment 12,such as triggering of a show effect, dispatch of a ride vehicle, closureof a gate, synchronization of security cameras with movement, and so on.More generally, the action may include the control of machine movement,image formation or adaptation, and similar processes.

As illustrated, the retro-reflective marker 24 is positioned on anobject 26, which may correspond to any number of static or dynamicfeatures. For instance, the object 26 may represent boundary features ofan amusement park attraction, such as a floor, a wall, a gate, or thelike, or may represent an item wearable by a guest, park employee, orsimilar object. Indeed, as set forth below, within an amusement parkattraction area, many such retro-reflective markers 24 may be present,and the tracking system 10 may detect reflection from some or all of themarkers 24, and may perform various analyses based on this detection.

Referring now to the operation of the tracking system 10, the emitter 14operates to emit electromagnetic radiation, which is represented by anexpanding electromagnetic radiation beam 28 electromagnetic radiationbeam 28 for illustrative purposes, to selectively illuminate, bathe, orflood a detection area 30 in the electromagnetic radiation.Electromagnetic radiation beam 28 is intended to generally represent anyform of electromagnetic radiation that may be used in accordance withpresent embodiments, such as forms of light (e.g., infrared, visible,UV) and/or other bands of the electromagnetic spectrum (e.g., radiowaves and so forth). However, it is also presently recognized that, incertain embodiments, it may be desirable to use certain bands of theelectromagnetic spectrum depending on various factors. For example, inone embodiment, it may be desirable to use forms of electromagneticradiation that are not visible to the human eye or within an audiblerange of human hearing, so that the electromagnetic radiation used fortracking does not distract guests from their experience. Further, it isalso presently recognized that certain forms of electromagneticradiation, such as certain wavelengths of light (e.g., infrared) may bemore desirable than others, depending on the particular setting (e.g.,whether the setting is “dark,” or whether people are expected to crossthe path of the beam). Again, the detection area 30 may correspond toall or a part of an amusement park attraction area, such as a stageshow, a ride vehicle loading area, a waiting area outside of an entranceto a ride or show, and so forth.

The electromagnetic radiation beam 28, in certain embodiments, may berepresentative of multiple light beams (beams of electromagneticradiation) being emitted from different sources (all part of an emissionsubsystem). Further, in some embodiments the emitter 14 is configured toemit the electromagnetic radiation beam 28 at a frequency that has acorrespondence to a material of the retro-reflective marker 24 (e.g., isable to be reflected by the retro-reflective elements of the marker 24).For instance, the retro-reflective marker 24 may include a coating ofretro-reflective material disposed on a body of the object 26 or a solidpiece of material coupled with the body of the object 26. By way of morespecific but non-limiting example, the retro-reflective material mayinclude spherical and/or prismatic reflective elements that areincorporated into a reflective material to enable retro-reflection tooccur. Again, in certain embodiments many such retro-reflective markers24 may be present, and may be arranged in a particular pattern stored inthe memory 22 to enable further processing, analysis, and controlroutines to be performed by the control unit 18 (e.g., control system).

The retro-reflective marker 24 may reflect a majority of theelectromagnetic radiation (e.g., infrared, ultraviolet, visiblewavelengths, or radio waves and so forth) incident from theelectromagnetic radiation beam 28 back toward the detector 16 within arelatively well-defined cone having a central axis with substantiallythe same angle as the angle of incidence. This reflection facilitatesidentification of a location of the retro-reflective marker 24 by thesystem 10 and correlation thereof to various information stored in thememory 22 (e.g., patterns, possible locations). This locationinformation (obtained based on the reflected electromagnetic radiation)may then be utilized by the control unit 18 to perform various analysisroutines and/or control routines, for example to determine whether tocause triggering or other control of the amusement park equipment 12.

Specifically, in operation, the detector 16 of the system 10 mayfunction to detect the electromagnetic radiation beam 28 retro-reflectedfrom the retro-reflective marker 24 and provide data associated with thedetection to the control unit 18 via communication lines 31 forprocessing. The detector 16 may operate to specifically identify themarker 24 based on certain specified wavelengths of electromagneticradiation emitted and reflected and, thus, avoid issues with falsedetections. For example, the detector 16 may be specifically configuredto detect certain wavelengths of electromagnetic radiation (e.g.,corresponding to those emitted by the emitter 14) through the use ofphysical electromagnetic radiation filters, signal filters, and thelike. Further, the detector 16 may utilize a specific arrangement ofoptical detection features and electromagnetic radiation filters tocapture substantially only retro-reflected electromagnetic radiation.

For example, the detector 16 may be configured to detect wavelengths ofelectromagnetic radiation retro-reflected by the retro-reflectivemarkers 24 while filtering wavelengths of electromagnetic radiation notretro-reflected by the markers 24, including those wavelengths ofinterest. Thus, the detector 16 may be configured to specifically detect(e.g., capture) retro-reflected electromagnetic radiation while notdetecting (e.g., capturing) electromagnetic radiation that is notretro-reflected. In one embodiment, the detector 16 may utilize thedirectionality associated with retro-reflection to perform thisselective filtering. Accordingly, while the detector 16 receiveselectromagnetic radiation from a variety of sources (includingspuriously reflected electromagnetic radiation, as well as environmentalelectromagnetic radiation), the detector 16 is specifically configuredto filter out all or substantially all spuriously reflected signalswhile retaining all or substantially all intended signals. Thus, thesignal-to-noise ratio of signals actually processed by the detector 16and control unit 18 is very high, regardless of the signal-to-noiseratio that exists for the electromagnetic bands of interest outside ofthe detector 16.

For example, the detector 16 may receive retro-reflected electromagneticradiation (e.g., from the retro-reflective markers 24) and ambientelectromagnetic radiation from within an area (e.g., guest attractionarea). The ambient electromagnetic radiation may be filtered, while theretro-reflected electromagnetic radiation, which is directional, may notbe filtered (e.g., may bypass the filter). Thus, in certain embodiments,the “image” generated by the detector 16 may include a substantiallydark (e.g., black or blank) background signal, with substantially onlyretro-reflected electromagnetic radiation producing contrast.

In accordance with certain embodiments, the retro-reflectedelectromagnetic radiation may include different wavelengths that aredistinguishable from one another. In one embodiment, the filters of thedetector 16 may have optical qualities and may be positioned within thedetector such that the optical detection devices of the detector 16substantially only receive electromagnetic wavelengths retro-reflectedby the retro-reflective markers 24 (or other retro-reflective elements),as well as any desired background wavelengths (which may providebackground or other landscape information). To produce signals from thereceived electromagnetic radiation, as an example, the detector 16 maybe a camera having a plurality of electromagnetic radiation capturingfeatures (e.g., charge-coupled devices (CCDs) and/or complementary metaloxide semiconductor (CMOS) sensors corresponding to pixels). In oneexample embodiment, the detector 16 may be an Amp® high dynamic range(HDR) camera system available from Contrast Optical Design andEngineering, Inc. of Albuquerque, N. Mex.

Because retro-reflection by the retro-reflective markers 24 is such thata cone of reflected electromagnetic radiation is incident on thedetector 16, the control unit 18 may in turn correlate a center of thecone, where the reflected electromagnetic radiation is most intense, toa point source of the reflection. Based on this correlation, the controlunit 18 may identify and track a location of this point source, or mayidentify and monitor a pattern of reflection by many suchretro-reflective markers 24.

For instance, once the control unit 18 receives the data from thedetector 16, the control unit 18 may employ known visual boundaries oran established orientation of the detector 16 to identify a location(e.g., coordinates) corresponding to the detected retro-reflectivemarker 24. When multiple stationary retro-reflective markers 24 arepresent, the control unit 18 may store known positions (e.g., locations)of the retro-reflective markers 24 to enable reflection patternmonitoring. By monitoring a reflection pattern, the control unit 18 mayidentify blockage (occlusion) of certain retro-reflective markers 24 byvarious moving objects, guests, employees, and so forth. It should alsobe noted that the bases for these comparisons may be updated based on,for example, how long a particular retro-reflective marker 24 has beenpositioned and used in its location. For instance, the stored pattern ofreflection associated with one of the markers 24 may be updatedperiodically during a calibration stage, which includes a time periodduring which no objects or people are expected to pass over the marker24. Such re-calibrations may be performed periodically so that a markerthat has been employed for an extended period of time and has lost itsretro-reflecting capability is not mistaken for a detected occlusionevent.

In other embodiments, in addition to or in lieu of tracking one or moreof the retro-reflective markers 24, the tracking system 10 may beconfigured to detect and track various other objects located within thedetection area 30. Such objects 32 may include, among other things, ridevehicles, people (e.g., guests, employees), and other moving parkequipment. For example, the detector 16 of the system 10 may function todetect the electromagnetic radiation beam 28 bouncing off of an object32 (without retro-reflective markers 24) and provide data associatedwith this detection to the control unit 18. That is, the detector 16 maydetect the object 32 based entirely on diffuse or specular reflection ofelectromagnetic energy off the object 32. In some embodiments, theobject 32 may be coated with a particular coating that reflects theelectromagnetic radiation beam 28 in a detectable and predeterminedmanner. Accordingly, once the control unit 18 receives the data from thedetector 16, the control unit 18 may determine that the coatingassociated with the object 32 reflected the electromagnetic radiation,and may also determine the source of the reflection to identify alocation of the object 32.

Whether the retro-reflective markers 24 are stationary or moving, theprocess of emitting the electromagnetic radiation beam 28, sensing ofthe reflected electromagnetic radiation from the retro-reflectivemarkers 24 (or objects 32 with no or essentially no retro-reflectivematerial), and determining a location of the retro-reflective marker 24or object 32 may be performed by the control unit 18 numerous times overa short period. This process may be performed at distinct intervals,where the process is initiated at predetermined time points, or may beperformed substantially continuously, such that substantiallyimmediately after the process is completed, it is re-initiated. Inembodiments where the retro-reflective markers 24 are stationary and thecontrol unit 18 performs retro-reflective pattern monitoring to identifymarker blockage, the process may be performed at intervals to obtain asingle retro-reflective pattern at each interval. This may be consideredto represent a single frame having a reflection pattern corresponding toa pattern of blocked and unblocked retro-reflective markers 24.

On the other hand, such procedures may essentially be performedcontinuously to facilitate identification of a path and/or trajectorythrough which the retro-reflective marker 24 has moved. The marker 24,moving within the detection area 30, would be detected over a particulartimeframe or simply in continuous series. Here, the pattern ofreflection would be generated and identified over a time period.

In accordance with the embodiments set forth above, the detector 16 andcontrol unit 18 may operate on a variety of different timeframesdepending on the tracking to be performed and the expected movement ofthe tracked object through space and time. As an example, the detector16 and the control unit 18 may operate in conjunction to complete alllogical processes (e.g., updating analysis and control signals,processing signals) in the time interval between the capture events ofthe detector 16. Such processing speeds may enable substantiallyreal-time tracking, monitoring, and control where applicable. By way ofnon-limiting example, the detector capture events may be betweenapproximately 1/60 of a second and approximately 1/30 of a second, thusgenerating between 30 and 60 frames per second. The detector 16 and thecontrol unit 18 may operate to receive, update, and process signalsbetween the capture of each frame. However, any interval between captureevents may be utilized in accordance with certain embodiments.

Once a particular pattern of retro-reflection has been detected, adetermination may be made by the control unit 18 as to whether thepattern correlates to a stored pattern identified by the control unit 18and corresponding to a particular action to be performed by theamusement park equipment 12. For example, the control unit 18 mayperform a comparison of a position, path, or trajectory of theretro-reflective marker 24 with stored positions, paths, or trajectoriesto determine an appropriate control action for the equipment 12.Additionally or alternatively, as described in further detail below, thecontrol unit 18 may determine whether a particular pattern obtained at aparticular time point correlates to a stored pattern associated with aparticular action to be performed by the amusement park equipment 12.Further still, the control unit 18 may determine whether a set ofparticular patterns obtained at particular time points correlate to astored pattern change associated with a particular action to beperformed by the amusement park equipment 12.

While the control unit 18 may cause certain actions to be automaticallyperformed within the amusement park in the manner set forth above, itshould be noted that similar analyses to those mentioned above may alsobe applied to the prevention of certain actions (e.g., where the parkequipment 12 blocks action or is blocked from performing an action). Forexample, in situations where a ride vehicle can be automaticallydispatched, the control unit 18, based upon tracking changes in theretro-reflective markers 24, may halt automatic dispatching, or may evenprevent dispatching by a ride operator until additional measures aretaken (e.g., additional confirmations that the ride vehicle is clearedfor departure). This type of control may be applied to other amusementpark equipment, as well. For example, flame effects, fireworks, orsimilar show effects may be blocked from being triggered, may bestopped, or may be reduced in intensity, due to intervention by thecontrol unit 18 as a result of certain pattern determinations asdescribed herein.

Having generally described the configuration of the system 10, it shouldbe noted that the arrangement of the emitter 14, detector 16, controlunit 18, and other features may vary based on application-specificconsiderations and the manner in which the control unit 18 performsevaluations based on electromagnetic radiation from the retro-reflectivemarkers 24. In the embodiment of the tracking system 10 illustrated inFIG. 1, the emitter 14 and the sensor or detector 16 are integralfeatures such that a plane of operation associated with the detector 16is essentially overlapping with a plane of operation associated with theemitter 14. That is, the detector 16 is located in substantially thesame position as the emitter 14, which may be desirable due to theretro-reflectivity of the markers 24. However, the present disclosure isnot necessarily limited to this configuration. For instance, as notedabove, retro-reflection may be associated with a cone of reflection,where the highest intensity is in the middle of the reflected cone.Accordingly, the detector 16 may be positioned within an area where thereflected cone of the retro-reflective markers is less intense than itscenter, but may still be detected by the detector 16.

By way of non-limiting example, in some embodiments, the emitter 14 andthe detector 16 may be concentric. However, the detector 16 (e.g., aninfrared camera) may be positioned in a different location with respectto the emitter 14, which may include an infrared light bulb, one or morediode emitters, or similar source. As illustrated in FIG. 2, the emitter14 and detector 16 are separate and are positioned at differentlocations on an environmental feature 40 of an amusement attraction area(e.g., a wall or ceiling). Specifically, the emitter 14 of FIG. 2 ispositioned outside of a window 42 of a storefront containing othercomponents of the system 10. The detector 16 of FIG. 2 is positionedaway from the emitter 14, but is still oriented to detectelectromagnetic radiation reflected from the retro-reflective marker 24and originating from the emitter 14.

For illustrative purposes, arrows 44, 46 represent a light beam (a beamof electromagnetic radiation) being emitted from the emitter 14 (arrow44) into the detection area 30, retro-reflected by the retro-reflectivemarker 24 on the object 26 (arrow 46), and detected by the detector 16.The light beam represented by the arrow 44 is merely one of numerouselectromagnetic radiation emissions (light beams) that flood orotherwise selectively illuminate the detection area 30 from the emitter14. It should be noted that still other embodiments may utilizedifferent arrangements of components of the system 10 andimplementations in different environments in accordance with the presentdisclosure.

Having now discussed the general operation of the tracking system 10 todetect a position of retro-reflective markers 24 and/or objects 32, asillustrated in FIG. 1, certain applications of the tracking system 10will be described in further detail below. For example, it may bedesirable to track the locations of people within a particular areathrough the use of the disclosed tracking systems. This may be useful,for example, for controlling lines in a ride vehicle loading area,controlling access to different areas, determining appropriate instanceswhen show effects can be triggered, determining appropriate instanceswhen certain automated machinery can be moved, and may also be usefulfor assisting a live show performance (e.g., blocking actors on astage). That is, during performances, actors are supposed to be standingat particular positions on the stage at certain times. To ensure thatthe actors are hitting their appropriate positions at the right time,the tracking system 10 may be installed above the stage and used totrack the positions and/or motion of all the actors on the stage.Feedback from the tracking system 10 may be utilized to evaluate howwell the actors are hitting the desired spots on the stage.

In addition to blocking on a stage, the tracking system 10 may be usedin contexts that involve tracking and/or evaluating shoppers in a storeor other commercial setting. That is, a store may be outfitted with thedisclosed tracking systems 10 in order to determine where guests arespending time within the store. Instead of triggering a show effect,such tracking systems 10 may be used to monitor the flow of peoplewithin the store and control the availability of certain items as aresult, control the flow of movement of people, etc. For instance,information collected via the disclosed tracking systems 10 may be usedto identify and evaluate which setups or displays within the store aremost attractive, to determine what items for sale are the most popular,or to determine which areas of the store, if any, are too crowded. Thisinformation may be analyzed and used to improve the store layout,product development, and crowd management, among other things.

It should be noted that other applications may exist for trackingpositions of people, objects, machines, etc. within an area other thanthose described above. Presently disclosed tracking systems 10 may beconfigured to identify and/or track the position and movement of peopleand/or objects within the detection area 30. The tracking system 10 mayaccomplish this tracking in several different ways, which wereintroduced above and are explained in further detail below. It should benoted that the tracking system 10 is configured to detect a position ofone or more people, one or more objects 32, or a combination ofdifferent features, at the same time in the same detection area 30 usingthe single emitter 14, detector 16, and control unit 18. However, theuse of multiple such emitters 14, detectors 16, and control units 18 isalso within the scope of the present disclosure. Accordingly, there maybe one or more of the emitters 14 and one or more of the detectors 16 inthe detection area 30. Considerations such as the type of tracking to beperformed, the desired range of tracking, for redundancy, and so forth,may at least partially determine whether multiple or a single emitterand/or detector are utilized.

For instance, as noted above, the tracking system 10 may generally beconfigured to track a target moving in space and in time (e.g., withinthe detection area 30 over time). When a single detection device (e.g.,detector 16) is utilized, the tracking system 10 may monitorretro-reflected electromagnetic radiation from a defined orientation totrack a person, object, etc. Because the detector 16 has only oneperspective, such detection and tracking may, in some embodiments, belimited to performing tracking in only one plane of movement (e.g., thetracking is in two spatial dimensions). Such tracking may be utilized,as an example, in situations where the tracked target has a relativelylow number of degrees of freedom, such as when movement is restricted toa constrained path (e.g., a track). In one such embodiment, the targethas a determined vector orientation.

On the other hand, when multiple detection devices are utilized (e.g.,two or more of the detectors 16) to track a target in both space andtime, the tracking system 10 may monitor retro-reflected electromagneticradiation from multiple orientations. Using these multiple vantagepoints, the tracking system 10 may be able to track targets havingmultiple degrees of freedom. In other words, the use of multipledetectors may provide both vector orientation and range for the trackedtarget. This type of tracking may be particularly useful in situationswhere it may be desirable to allow the tracked target to haveunrestricted movement in space and time.

Multiple detectors may also be desirable for redundancy in the tracking.For example, multiple detection devices applied to scenarios wheremovement of the target is restricted, or not, may enhance thereliability of the tracking performed by the tracking system 10. The useof redundant detectors 16 may also enhance tracking accuracy, and mayhelp prevent geometric occlusion of the target by complex geometricsurfaces, such as winding pathways, hills, folded clothing, openingdoors, and so on.

In accordance with one aspect of the present disclosure, the trackingsystem 10 may track relative positions of multiple targets (e.g.,people, objects, machines) positioned within the detection area 30through the use of the retro-reflective markers 24. As illustrated inFIG. 3, the retro-reflective markers 24 may be disposed on a person 70.Additionally or alternatively, the marker 24 may be positioned on amachine or other object (e.g., object 26). Accordingly, the techniquesdisclosed herein for tracking movement of the person 70 in space andtime may also be applied to movement of an object in the amusement park,either in addition to the person 70 or as an alternative to the person70. In such embodiments, the marker 24 may be positioned on an outsideof the object 26 (e.g., a housing), as shown in FIG. 1.

In the illustrated embodiment of FIG. 3, the retro-reflective marker 24is disposed on the outside of the person's clothing. For instance, theretro-reflective marker 24 may be applied as a strip of retro-reflectivetape applied to an armband, headband, shirt, personal identificationfeature, or other article. Additionally or alternatively, theretro-reflective marker 24 may, in some embodiments, be sewn intoclothing or applied to the clothing as a coating. The retro-reflectivemarker 24 may be disposed on the clothing of the person 70 in a positionthat is accessible to the electromagnetic radiation beam 28 beingemitted from the emitter 14. As the person 70 walks about the detectionarea 30 (in the case of the object 32, the object 32 may move throughthe area 30), the electromagnetic radiation beam 28 reflects off theretro-reflective marker 24 and back to the detector 16. The detector 16communicates with the control unit 18 by sending a signal 72 to theprocessor 20, this signal 72 being indicative of the reflectedelectromagnetic radiation detected via the detector 16. The trackingsystem 10 may interpret this signal 72 to track the position or path ofthe person 70 (or object 32) moving about a designated area (i.e., trackthe person or object in space and time). Again, depending on the numberof detectors 16 utilized, the control unit 18 may determine vectormagnitude, orientation, and sense of the person and/or object's movementbased on the retro-reflected electromagnetic radiation received.

The tracking of the person 70 (which may also be representative of amoving object) is illustrated schematically in FIG. 4. Morespecifically, FIG. 4 illustrates a series 80 of frames 82 captured bythe detector 16 (e.g., camera) over a period of time. As noted above, aplurality of such frames (e.g., between 30 and 60) may be generatedevery second in certain embodiments. It should be noted that FIG. 4 maynot be an actual representation of outputs produced by the trackingsystem 10, but is described herein to facilitate an understanding of thetracking and monitoring performed by the control unit 18. The frames 82each represent the detection area 30, and the position of theretro-reflective marker 24 within the area 30. Alternatively, the frames82 may instead represent marker blockage within the area 30, for examplewhere a grid of markers 24 are occluded by an object or person.

As shown, a first frame 82A includes a first instance of theretro-reflective marker, designated as 24A, having a first position. Asthe series 80 progresses in time, a second frame 82B includes a secondinstance of the retro-reflective marker 24B, which is displaced relativeto the first instance, and so on (thereby producing third and fourthinstances of the retro-reflective marker 24C and 24D). After a certainperiod of time, the control unit 18 has generated the series 80, wherethe operation of generating the series 80 is generally represented byarrow 84.

The series 80 may be evaluated by the control unit 18 in a number ofdifferent ways. In accordance with the illustrated embodiment, thecontrol unit 18 may evaluate movement of the person 70 or object 32 byevaluating the positions of the marker 24 (or blockage of certainmarkers) over time. For example, the control unit 18 may obtain vectororientation, range, and sense, relating to the movement of the trackedtarget depending on the number of detectors 16 utilized to perform thetracking. In this way, the control unit 18 may be considered to evaluatea composite frame 86 representative of the movement of the trackedretro-reflective marker 24 (or tracked blockage of markers 24) over timewithin the detection area 30. Thus, the composite frame 86 includes thevarious instances of the retro-reflective marker 24 (including 24A, 24B,24C, 24D), which may be analyzed to determine the overall movement ofthe marker 24 (and, therefore, the person 70 and/or object 26, whicheverthe case may be).

As also illustrated in FIG. 4, this monitoring may be performed relativeto certain environmental elements 88, which may be fixed within thedetection area 30 and/or may be associated with reflective materials.The control unit 18 may perform operations not only based on thedetected positions of the marker 24, but also based on extrapolatedmovement (e.g., a projected path of the retro-reflective marker 24through the detection area 30 or projected positions of marker gridocclusion) in relation to the environmental elements 88.

Another method for tracking one or more people 70 or objects 32 in anarea is illustrated schematically in FIG. 5. Specifically, FIG. 5represents an overhead view of a group of people 70 standing in thedetection area 30. Although not illustrated, the tracking system 10 maybe present directly above this detection area 30 in order to detectpositions of people 70 (and other objects) present within the detectionarea 30 (e.g., to obtain a plan view of the detection area 30). In theillustrated embodiment, the retro-reflective markers 24 are positionedin a grid pattern 90 on a floor 92 of the detection area 30 (e.g., as acoating, pieces of tape, or similar attachment method). Theretro-reflective markers 24 may be arranged in any desired pattern(e.g., grid, diamond, lines, circles, solid coating, etc.), which may bea regular pattern (e.g., repeating) or a random pattern.

This grid pattern 90 may be stored in the memory 22, and portions of thegrid pattern 90 (e.g., individual markers 24) may be correlated tolocations of certain environmental elements and amusement park features(e.g., the amusement park equipment 12). In this way, the position ofeach of the markers 24 relative to such elements may be known.Accordingly, when the markers 24 retro-reflect the electromagneticradiation beam 28 to the detector 16, the location of the markers 24that are reflecting may be determined and/or monitored by the controlunit 18.

As illustrated, when the people 70 or objects 32 are positioned over oneor more of the retro-reflective markers 24 on the floor 92, the occludedmarkers cannot reflect the emitted electromagnetic radiation back to thedetector 16 above the floor 92. Indeed, in accordance with anembodiment, the grid pattern 90 may include retro-reflective markers 24that are spaced apart by a distance that allows the people or objectspositioned on the floor 92 to be detectable (e.g., blocking at least oneof the retro-reflective markers 24). In other words, the distancebetween the markers 24 may be sufficiently small so that objects orpeople may be positioned over at least one of the retro-reflectivemarkers 24.

In operation, the detector 16 may function to detect the electromagneticradiation beam 28 retro-reflected from the retro-reflective markers 24that are not covered up by people or objects located in the detectionarea 30. As discussed above, the detector 16 may then provide dataassociated with this detection to the control unit 18 for processing.The control unit 18 may perform a comparison of the detectedelectromagnetic radiation beam reflected off the uncoveredretro-reflective markers 24 (e.g., a detected pattern) with storedpositions of the completely uncovered grid pattern 90 (e.g., a storedpattern) and/or other known grid patterns resulting from blockage ofcertain markers 24. Based on this comparison, the control unit 18 maydetermine which markers 24 are covered to then approximate locations ofthe people 70 or objects 32 within the plane of the floor 92. Indeed,the use of a grid positioned on the floor 92 in conjunction with asingle detector 16 may enable the tracking of movement in twodimensions. If higher order tracking is desired, additional grids and/oradditional detectors 16 may be utilized. In certain embodiments, basedon the locations of the people 70 or objects 32 in the detection area30, the control unit 18 may adjust the operation of the amusement parkequipment 12.

The process of emitting the electromagnetic radiation beam 28, sensingof the reflected electromagnetic radiation from the uncoveredretro-reflective markers 24 on the floor 92, and determining a locationof the people 70 may be performed by the control unit 18 numerous timesover a short period in order to identify a series of locations of thepeople 70 moving about the floor 92 (to track motion of the group).Indeed, such procedures may essentially be performed continuously tofacilitate identification of a path through which the people 70 havemoved within the detection area 30 during a particular timeframe orsimply in continuous series. Once the position or path one or more ofthe people 70 has been detected, the control unit 18 may further analyzethe position or path to determine whether any actions should beperformed by the equipment 12.

As discussed in detail above with respect to FIG. 1, the control unit 18may be configured to identify certain objects that are expected to crossthe path of the electromagnetic radiation beam 28 within the detectionarea 30, including objects that are not marked with retro-reflectivematerial. For example, as illustrated in FIG. 6, some embodiments of thetracking system 10 may be configured such that the control unit 18 isable to identify the person 70 (which is also intended to berepresentative of the object 32) located in the detection area 30,without the use of the retro-reflective markers 24. That is, the controlunit 18 may receive data indicative of the electromagnetic radiationreflected back from the detection area 30, and the control unit 18 maycompare a digital signature of the detected radiation to one or morepossible data signatures stored in memory 22. That is, if the signatureof electromagnetic radiation reflected back to the detector 16 matchesclosely enough to the signature of a person 70 or known object 32, thenthe control unit 18 may determine that the person 70 or object 32 islocated in the detection area 30. For example, the control unit 18 mayidentify “dark spots,” or regions where electromagnetic radiation wasabsorbed rather than reflected, within the detection area 30. Theseareas may have a geometry that the control unit 18 may analyze (e.g., bycomparing to shapes, sizes, or other features of stored objects orpeople) to identify a presence, location, size, shape, etc., of anobject (e.g., the person 70).

As may be appreciated with reference to FIGS. 1, 2, 3, and 6, thetracking system 10 may be positioned in a variety of locations to obtaindifferent views of the detection area 30. Indeed, it is now recognizedthat different locations and combinations of locations of one or more ofthe tracking systems 10 (or one or more elements of the tracking system10, such as multiple detectors 16) may be desirable for obtainingcertain types of information relating to the retro-reflective markers 24and the blockage thereof. For instance, in FIG. 1, the tracking system10, and in particular the detector 16, is positioned to obtain anelevational view of at least the object 26 fitted with theretro-reflective marker 24 and the object 32. In FIG. 2, the detector 16is positioned to obtain an overhead perspective view of the detectionarea 30, which enables detection of retro-reflective markers 24positioned on a variety of environmental elements, moving objects, orpeople. In the embodiments of FIGS. 3 and 6, the detector 16 may bepositioned to obtain a plan view of the detection area 30.

These different views may provide information that may be utilized bythe control unit 18 for specific types of analyses and, in certainembodiments, control actions that may depend on the particular settingin which they are located. For example, in FIG. 7, the tracking system10, and particularly the emitter 14 and the detector 16, are positionedto obtain a perspective view of the person 70 (or object 32) in thedetection area 30. The detection area 30 includes the floor 92, but alsoincludes a wall 93 on which the retro-reflective markers 24 arepositioned to form the grid pattern 90. Here, the person 70 is blockinga subset of markers 24 positioned on the wall 93. The subset of markers24 are unable to be illuminated by the emitter 14, are unable toretro-reflect the electromagnetic radiation back to the detector 16, orboth, because the person 70 (also intended to represent an object) ispositioned between the subset of markers 24 and the emitter 14 and/ordetector 16.

The grid pattern 90 on the wall 93 may provide information notnecessarily available from a plan view as shown in FIGS. 3 and 6. Forexample, the blockage of the retro-reflective markers 24 enables thecontrol unit 18 to determine a height of the person 70, a profile of theperson 70, or, in embodiments where there the object 32 is present, asize of the object 32, a profile of the object 32, and so forth. Suchdeterminations may be made by the control unit 18 to evaluate whetherthe person 70 meets a height requirement for a ride, to evaluate whetherthe person 70 is associated with one or more objects 32 (e.g., bags,strollers), and may also be used to track movement of the person 70 orobject 32 through the detection area 30 with a greater degree ofaccuracy compared to the plan view set forth in FIGS. 3 and 6. That is,the control unit 18 is better able to tie movement identified byblockage of the markers 24 to a particular person 70 by determining theperson's profile, height, etc. Similarly, the control unit 18 is betterable to track the movement of the object 32 through the detection area30 by identifying the geometry of the object 32, and tying identifiedmovement specifically to the object 32. In certain embodiments, trackingthe height or profile of the person 70 may be performed by the trackingsystem 10 to enable the control unit 18 to provide recommendations tothe person 70 based on an analysis of the person's evaluated height,profile, etc. Similar determinations and recommendations may be providedfor objects 32, such as vehicles. For example, the control unit 18 mayanalyze a profile of guests at an entrance to a queue area for a ride.The control unit 18 may compare the overall size, height, etc., of theperson 70 with ride specifications to warn individuals or provide aconfirmation that they are able to ride the ride before spending time inthe queue. Similarly, the control unit 18 may analyze the overall size,length, height, etc., of a vehicle to provide parking recommendationsbased on available space. Additionally or alternatively, the controlunit 18 may analyze the overall size, profile, etc., of an automatedpiece equipment before allowing the equipment to perform a particulartask (e.g., movement through a crowd of people).

The pattern 90 may also be positioned on both the wall 93 and the floor92. Accordingly, the tracking system 10 may be able to receiveretro-reflected electromagnetic radiation from markers 24 on the wall 93and the floor 92, thereby enabling detection of marker blockage andmonitoring of movement in three dimensions. Specifically, the wall 93may provide information in a height direction 94, while the floor 92 mayprovide information in a depth direction 96. Information from both theheight direction 94 and the depth direction 96 may be correlated to oneanother using information from a width direction 98, which is availablefrom both the plan and elevational views.

Indeed, it is now recognized that if two objects 32 or people 70 overlapin the width direction 98, they may be at least partially resolved fromone another using information obtained from the depth direction 96.Further, it is also now recognized that the use of multiple emitters 14and detectors 16 in different positions (e.g., different positions inthe width direction 98) may enable resolution of height and profileinformation when certain information may be lost or not easily resolvedwhen only one emitter 14 and detector 16 are present. More specifically,using only one emitter 14 and detector 16 may result in a loss ofcertain information if there is overlap between objects 32 or people 70in the width direction 98 (or, more generally, overlap in a directionbetween the markers 24 on the wall 93 and the detector 16). However,embodiments using multiple (e.g., at least two) detectors 16 and/oremitters 14 may cause distinct retro-reflective patterns to be producedby the markers 24 and observed from the detectors 16 and/or emitters 14positioned at different perspectives. Indeed, because the markers 24 areretro-reflective, they will retro-reflect electromagnetic radiation backtoward the electromagnetic radiation source, even when multiple sourcesemit at substantially the same time. Thus, electromagnetic radiationemitted from a first of the emitters 14 from a first perspective will beretro-reflected back toward the first of the emitters 14 by the markers24, while electromagnetic radiation emitted from a second of theemitters 14 at a second perspective will be retro-reflected back towardthe second of the emitters 14 by the markers 24, which enables multiplesets of tracking information to be produced and monitored by the controlunit 18.

It is also now recognized that the retro-reflective markers 24 on thewall 93 and the floor 92 may be the same, or different. Indeed, thetracking system 10 may be configured to determine which electromagneticradiation was reflected from the wall 93 versus which electromagneticradiation was reflected from the floor 92 using a directionality of theretro-reflected electromagnetic radiation from the wall 93 and the floor92. In other embodiments, different materials may be used for themarkers 24 so that, for example, different wavelengths ofelectromagnetic radiation may be reflected back toward the emitter 14and detector 16 by the different materials. As an example, theretro-reflective markers 24 on the floor 92 and the wall 93 may have thesame retro-reflective elements, but different layers that act to filteror otherwise absorb portions of the emitted electromagnetic radiation sothat electromagnetic radiation reflected by the retro-reflective markers24 on the floor 92 and wall 93 have characteristic and differentwavelengths. Because the different wavelengths would be retro-reflected,the detector 16 may detect these wavelengths and separate them fromambient electromagnetic radiation, which is filtered by filter elementswithin the detector 16.

To help illustrate, FIG. 8 depicts expanded cross-sectional views ofexample retro-reflective markers 24 disposed on the floor 92 and thewall 93 within the detection area 30. The markers 24 on the floor 92 andthe wall 93 each include a reflective layer 96 and a retro-reflectivematerial layer 98, which may be the same or different for the floor 92and wall 93. In the illustrated embodiment, they are the same. Duringoperation, electromagnetic radiation emitted by the emitter 14 maytraverse a transmissive coating 99 before striking the retro-reflectivematerial layer 98. Accordingly, the transmissive coating 99 may be usedto adjust the wavelengths of electromagnetic radiation that areretro-reflected by the markers. In FIG. 8, the markers 24 on the floor92 include a first transmissive coating 99A, which is different than asecond transmissive coating 99B in the markers 24 on the wall 93. Incertain embodiments, different optical properties between the first andsecond transmissive coatings 99A, 99B may cause a different bandwidth ofelectromagnetic radiation to be reflected by the markers 24 on the floor92 and the markers 24 on the wall 93. While presented in the context ofbeing disposed on the floor 92 and the wall 93, it should be noted thatmarkers 24 having different optical properties may be used on a varietyof different elements within the amusement park, such as on people andenvironmental elements, people and moving equipment, and so on, tofacilitate separation for processing and monitoring by the control unit18.

Any one or a combination of the techniques set forth above may be usedto monitor a single object or person, or multiple objects or people.Indeed, it is presently recognized that a combination of multipleretro-reflective marker grids (e.g., on the floor 92 and wall 93 as setforth above), or a combination of one or more retro-reflective markergrids and one or more tracked retro-reflective markers 24 fixed on amovable object or person, may be utilized to enable three-dimensionaltracking, even when only one detector 16 is utilized. Further, it isalso recognized that using multiple retro-reflective markers 24 on thesame person or object may enable the tracking system 10 to track bothposition and orientation.

In this regard, FIG. 9A illustrates an embodiment of the object 26having multiple retro-reflective markers 24 positioned on differentfaces of the object 26. Specifically, in the illustrated embodiment, theretro-reflective markers 24 are disposed on three different points ofthe object 26 corresponding to three orthogonal directions (e.g., X, Y,and Z axes) of the object 26. However, it should be noted that otherplacements of the multiple retro-reflective markers 24 may be used inother embodiments. In addition, the tracking depicted in FIG. 9A may beperformed as generally illustrated, or may also utilize a grid of theretro-reflective markers 24 as shown in FIG. 7.

As noted above, the tracking system 10 may include multiple detectors 16configured to sense the electromagnetic radiation that is reflected backfrom the object 26, for example. Each of the retro-reflective markers 24disposed on the object 26 may retro-reflect the emitted electromagneticradiation beam 28 at a particular, predetermined frequency of theelectromagnetic spectrum of the electromagnetic radiation beam 28. Thatis, the retro-reflective markers 24 may retro-reflect the same ordifferent portions of the electromagnetic spectrum, as generally setforth above with respect to FIG. 8.

The control unit 18 is configured to detect and distinguish theelectromagnetic radiation reflected at these particular frequencies and,thus, to track the motion of each of the separate retro-reflectivemarkers 24. Specifically, the control unit 18 may analyze the detectedlocations of the separate retro-reflective markers 24 to track the roll(e.g., rotation about the Y axis), pitch (e.g., rotation about the Xaxis), and yaw (e.g., rotation about the Z axis) of the object 26. Thatis, instead of only determining the location of the object 26 in spacerelative to a particular coordinate system (e.g., defined by thedetection area 30 or the detector 16), the control unit 18 may determinethe orientation of the object 26 within the coordinate system, whichenables the control unit 18 to perform enhanced tracking and analyses ofthe movement of the object 26 in space and time through the detectionarea 30. For instance, the control unit 18 may perform predictiveanalyses to estimate a future position of the object 26 within thedetection area 30, which may enable enhanced control over the movementof the object 26 (e.g., to avoid collisions, to take a particular paththrough an area).

In certain embodiments, such as when the object 26 is a motorizedobject, the tracking system 10 may track the position and orientation ofthe object 26 (e.g., a ride vehicle, an automaton, an unmanned aerialvehicle) and control the object 26 to proceed along a path in apredetermined manner. The control unit 18 may, additionally oralternatively, compare the results to an expected position andorientation of the object 26, for example to determine whether theobject 26 should be controlled to adjust its operation, and/or todetermine whether the object 26 is operating properly or is in need ofsome sort of maintenance. In addition, the estimated position andorientation of the object 26, as determined via the tracking system 10,may be used to trigger actions (including preventing certain actions) byother amusement park equipment 12 (e.g., show effects). As one example,the object 26 may be a ride vehicle and the amusement park equipment 12may be a show effect. In this example, it may be desirable to onlytrigger the amusement park equipment 12 when the object 26 is in theexpected position and/or orientation.

Continuing with the manner in which tracking in three spatial dimensionsmay be preformed, FIG. 9B depicts an example of the object having afirst marker 24A, a second marker 24B, and a third marker 24C positionedin similar positions as set forth in FIG. 9A. However, from theperspective of a single one of the detectors 16, the detector 16 may seea two-dimensional representation of the object 16, and the markers 24A,24B, 24C. From this first perspective (e.g., overhead or bottom view),the control unit 18 may determine that the first and second markers 24A,24B are separated by a first observed distance d1, the first and thirdmarkers 24A, 24C are separated by a second observed distance d2, and thesecond and third markers 24B, 24C are separated by a third observeddistance d3. The control unit 18 may compare these distances to known orcalibrated values to estimate an orientation of the object 26 in threespatial dimensions.

Moving to FIG. 9C, as the object 26 rotates, the detector 16 (and,correspondingly, the control unit 18) may detect that the apparent shapeof the object 26 is different. However, the control unit 18 may alsodetermine that the first and second markers 24A, 24B are separated by anadjusted first observed distance d1′, the first and third markers 24A,24C are separated by an adjusted second observed distance d2′, and thesecond and third markers 24B, 24C are separated by an adjusted thirdobserved distance d3′. The control unit 18 may determine a differencebetween the distances detected in the orientation in FIG. 9B and thedistances detected in the orientation in FIG. 9C to determine how theorientation of the object 26 has changed to then determine theorientation of the object 26. Additionally or alternatively, the controlunit 18 may compare the adjusted observed distances d1′, d2′, d3′resulting from rotation of the object 26 to stored values to estimate anorientation of the object 26 in three spatial dimensions, or to furtherrefine an update to the orientation determined based on the changebetween the distances in FIGS. 9B and 9C.

As set forth above, present embodiments are directed to, among otherthings, the use of the disclosed tracking system 10 to track objectsand/or people within an amusement park environment. As a result of thistracking, the control unit 18 may, in some embodiments, cause certainautomated functions to be performed within various subsystems of theamusement park. Accordingly, having described the general operation ofthe disclosed tracking system 10, more specific embodiments of trackingand control operations are provided below to facilitate a betterunderstanding of certain aspects of the present disclosure.

Moving now to FIG. 10, an embodiment of a method 100 of monitoringchanges in reflected electromagnetic radiation to track movement of atarget and control amusement park equipment as result of this monitoringis illustrated as a flow diagram. Specifically, the method 100 includesthe use of one or more of the emitters 14 (e.g., an emission subsystem)to flood (block 102) the detection area 30 with electromagneticradiation (e.g., electromagnetic radiation beam 28) using the emissionsubsystem. For instance, the control unit 18 may cause one or more ofthe emitters 14 to intermittently or substantially continuously floodthe detection area 30 with emitted electromagnetic radiation. Again, theelectromagnetic radiation may be any appropriate wavelength that is ableto be retro-reflected by the retro-reflective markers 24. This includes,but is not limited to, ultraviolet, infrared, and visible wavelengths ofthe electromagnetic spectrum. It will be appreciated that differentemitters 14, and in some embodiments, different markers 24, may utilizedifferent wavelengths of electromagnetic radiation to facilitatedifferentiation of various elements within the area 30.

After flooding the detection area 30 with electromagnetic radiation inaccordance with the acts generally represented by block 102, the method100 proceeds to detecting (block 104) electromagnetic radiation that hasbeen reflected from one or more elements in the detection area 30 (e.g.,the retro-reflective markers 24). The detection may be performed by oneor more of the detectors 16, which may be positioned relative to theemitter 14 as generally set forth above with respect to FIGS. 1 and 2.As described above and set forth in further detail below, the featuresthat perform the detection may be any appropriate element capable of andspecifically configured to capture retro-reflected electromagneticradiation and cause the captured retro-reflective electromagneticradiation to be correlated to a region of the detector 16 so thatinformation transmitted from the detector 16 to the control unit 18retains position information regarding which of the markers 24 reflectedelectromagnetic radiation to the detector 16. As one specific butnon-limiting example, one or more of the detectors 16 (e.g., present asa detection subsystem) may include charge coupled devices within anoptical camera or similar feature.

As described above, during the course of operation of the trackingsystem 10, and while people 70 and/or objects 26, 32 are present withinthe detection area 30, it may be expected that changes in reflectedelectromagnetic radiation will occur. These changes may be tracked(block 106) using a combination of the one or more detectors 16 androutines performed by processing circuitry of the control unit 18. Asone example, tracking changes in the reflected electromagnetic radiationin accordance with the acts generally represented by block 106 mayinclude monitoring changes in reflected patterns from a grid over acertain period of time, monitoring changes in spectral signaturespotentially caused by certain absorptive and/or diffusively orspecularly reflective elements present within the detection area 30, orby monitoring certain moving retro-reflective elements. As describedbelow, the control unit 18 may be configured to perform certain types oftracking of the changes in reflection depending on the nature of thecontrol to be performed in a particular amusement park attractionenvironment.

At substantially the same time or shortly after tracking the changes inreflected electromagnetic radiation in accordance with the actsgenerally represented by block 106, certain information may be evaluated(block 108) as a result of these changes by the control unit 18. Inaccordance with one aspect of the present disclosure, the evaluatedinformation may include information pertaining to one or moreindividuals (e.g., amusement park guests, amusement park employees) toenable the control unit 18 to monitor movement and positioning ofvarious individuals, and/or make determinations relating to whether theperson is appropriately positioned relative to certain amusement parkfeatures. In accordance with another aspect of the present disclosure,the information evaluated by the control unit 18 may include informationrelating to objects 26, 32, which may be environmental objects, movingobjects, the amusement park equipment 12, or any other device, item, orother feature present within the detection area 30. Further detailsregarding the manner in which information may be evaluated is describedin further detail below with reference to specific examples of amusementpark equipment controlled at least in part by the control unit 18.

As illustrated, the method 100 also includes controlling (block 110)amusement park equipment based on the information (e.g., monitored andanalyzed movement of people and/or objects) evaluated in accordance withacts generally represented by block 108. It should be noted that thiscontrol may be performed in conjunction with concurrent tracking andevaluation to enable the control unit 18 to perform many of the stepsset forth in method 100 on a substantially continuous basis and inreal-time (e.g., on the order of the rate of capture of the detector16), as appropriate. In addition, the amusement park equipmentcontrolled in accordance with the acts generally represented by block110 may include automated equipment such as ride vehicles, access gates,point-of-sale kiosks, informational displays, or any other actuatableamusement park device. As another example, the control unit 18 maycontrol certain show effects such as the ignition of a flame or afirework as a result of the tracking and evaluation performed inaccordance with method 100. More details relating to certain of thesespecific examples are described in further detail below.

In accordance with a more particular aspect of the present disclosure,the present embodiments relate to the tracking of certain objects 26, 32and people 70 within an amusement park attraction area. In certainembodiments, park equipment may be controlled based on this information.The amusement park equipment controlled in accordance with presentembodiments may include, by way of example, automatons, automatedvehicles, unmanned aerial vehicles, show equipment (e.g., flames,fireworks), and so forth. In accordance with this aspect, FIG. 11illustrates an embodiment of a method 120 for monitoring patterns ofreflection to track and control automated amusement park equipment as aresult of monitoring either or both of people within an amusement parkarea.

As illustrated, the method 120 includes monitoring (block 122) a patternof reflection. The monitoring performed in accordance with the actsgenerally represented by block 122 may be considered to be performedusing the tracking system 10, either alone or in combination with otherfeatures of an amusement park control system. To facilitate discussion,the disclosure set forth below may refer to a control system that iscommunicatively coupled to a number of different devices including thetracking system 10, as well as the amusement park equipment to becontrolled.

Monitoring the pattern of reflection in accordance with block 122 mayinclude monitoring a number of different features in the mannerdescribed above with respect to FIGS. 3-9. Accordingly, the monitoringperformed in accordance with block 122 may include monitoring a patterngenerated over time by a marker being tracked within the detection area30, or may include monitoring a pattern of reflection generated at anyone time instance by a plurality of retro-reflective markers 24positioned within the detection area 30 (e.g., a grid), or a combinationof these techniques. Further still, the monitoring performed inaccordance with block 122 may not involve the use of the markers 24,such as in situations where the tracking system 10 is employed to trackspecular and/or diffuse reflection. In some embodiments, a combinationof these patterns may be monitored in accordance with block 122, forexample when one or more of the retro-reflective markers 24 ispositioned on the person 70, while other retro-reflective markers 24 arepositioned on other objects 32, the wall 93, the floor 92, or any otherenvironmental feature in the detection area 30.

The method 120 also includes determining (block 124) differences betweendetected patterns of reflection and stored patterns of reflection. Forexample, a detected pattern may be considered to be a pattern generatedeither at any one instance (e.g. using a grid) or over time by a singleor multiple tracked retro-reflective markers 24. The stored patterns maybe considered to represent patterns stored in the memory 22 of thecontrol unit 18, which may be correlated to different types ofinformation, such as behavioral information, certain types of movement,orientations, and/or locations, height or other geometric information,or the like. In one embodiment, the control unit 18 may determinedifferences between the detected pattern of reflection and the storedpattern of reflection to further determine whether the detected patterncorrelates to a particular control action associated with storedpattern, either based on this information alone or when the informationis considered in conjunction with additional a priori information (e.g.,prior knowledge of a desired travel path through an amusement park,prior knowledge of the size and shape of the object 26, 32).

The method 120 may also include using the identified position to causetriggering (including preventing) of automated park equipment (block128). For example, an identified position may cause the control unit 18to trigger a show effect, adjust an operational parameter of a ridevehicle, adjust an orientation, speed, etc., of a motorized object(e.g., a UAV), or similar actions. Further still, where certain showeffects are associated with a controlled object (e.g., a controlled ridevehicle), the show effects may be triggered based, at least in part, ona position, orientation, speed, etc., of the controlled object.

An example embodiment of an amusement park attraction and control system140 that may perform all or part of method 120 is depicted in FIG. 12.Specifically, the system 140 of FIG. 12 includes a control system 142,which may include processing circuitry configured to perform functionsthat are specific to a particular park attraction and coordinate thoseactions with the tracking system 10. Indeed, as illustrated, the controlsystem 142 may include the control unit 18. As also illustrated, thecontrol system 142 is communicatively coupled to an emission subsystem144, which includes one or more of the emitters 14, and a detectionsubsystem 146, which includes one or more of the detectors 16.

Using information obtained from the detection subsystem 146, as well asroutines and reference information stored in the processing circuitry ofthe control unit 18, the control system 142 may track, and in someembodiments, control automated attraction equipment 12 to which it iscommunicatively and/or operatively coupled. The particular embodiment ofthe amusement park attraction and control system 140 illustrated in FIG.12 is configured to perform various monitoring and control actions basedat least in part on monitoring patterns of reflection obtained fromretro-reflective markers 24 positioned on static and/or moving elementsof the detection area 30. As an example, the detection area 30 mayrepresent an attraction area of an amusement park where automated mobileobjects are configured to move about the attraction area forentertainment purposes, interactivity purposes, and so forth. Theoperation of the attraction equipment 12 is described in further detailbelow.

In the particular embodiment illustrated in FIG. 12, theretro-reflective markers 24 may be considered to be divided into a firstsubset 148 and a second subset 150. Each marker 24 of the first subset148 has a distance from the attraction equipment 12 that is at or belowa threshold distance from the attraction equipment 12. Indeed, the firstsubset 148 of retro-reflective markers 24 may be considered to representa proximity region of the attraction equipment 12, meaning that anyobject or person positioned over one or more of the retro-reflectivemarkers 24 of the first subset 148 may be considered to be positioned inclose proximity to the attraction equipment 12. On the other hand, themarkers 24 of the second subset 150 have a distance that is outside ofthe predetermined distance defining the first subset 148. Accordingly,the second subset 150 of markers 24 may be considered to be beyond(e.g., outside of) a proximity boundary 152 associated with theattraction equipment 12. Any object or person positioned over the secondsubset 150 may therefore be considered to not be in a close proximity tothe attraction equipment 12.

In accordance with an aspect of the present disclosure, the proximityboundary 152 may be determined based on the particular configuration ofthe attraction equipment 12. For example, if the attraction equipment 12is a motorized or movable object, the proximity boundary 152 may movewith the attraction equipment. Further, the degree of control of theattraction equipment 12 (e.g., the ability to perform fine control ofmovement of the attraction equipment 12) may also at least partiallydetermine the distance of the proximity boundary 152 from the attractionequipment 12.

In operation, the control system 142 may monitor, using the emissionsubsystem 144 and the detection subsystem 146, blockage (occlusion) ofcertain of the retro-reflective markers 24. As one example, the controlsystem 142 may monitor the first subset 148 of markers 24 and, as aresult of any identification that one or more of the markers 24 of thefirst subset 148 is blocked by an object or person, may cause theattraction equipment 12 to trigger (e.g., move). This triggering may,additionally or alternatively, be triggering of a show effect,triggering of an automated gate, or similar action. However, thetriggering of the attraction equipment 12 may not necessarily denotetriggering of an amusement feature. For instance, triggering of theattraction equipment 12, in some instances, may cause certain fail-safesto be engaged that prevent certain actions by the attraction equipment12. One example of such a control action might be to prevent movement ofthe attraction equipment 12 (e.g., prevention of movement of a robot).For example, as illustrated in FIG. 12, the attraction equipment 12 mayinclude or be associated with an actuation system 154, which may includevarious electromechanical drives, brakes, rotors, pumps, propellantrelease systems, or any other system capable of producing a motive forceto move the attraction equipment 12 through the detection area 30.

The attraction equipment 12 may, in some embodiments, include certaintypes of circuitry that facilitates communication and processing. Forinstance, while the attraction equipment 12 is shown as being incommunication with the control system 142 via a communication line 156,the communication between these features may be wired or wireless.Accordingly, in certain embodiments, the attraction equipment 12 mayinclude, for example, a transceiver 158 configured to enable thetransmission and receipt of signals from and to the attraction equipment12, respectively. The attraction equipment 12 may also includeprocessing circuitry configured to process input signals and carry outinstructions as a result of this processing. The processing circuitry isillustrated as including one or more processors 160 and one or morememory 162.

As an example, the control system 142 may relay position, orientation,and/or velocity information and instructions to the attraction equipment12 via the transceiver 158 (and communication equipment associated withthe control system 142), and the attraction equipment 12 may processthis information and instructions to make position, orientation, and/orvelocity adjustments using the actuation system 154.

As set forth above, the presently disclosed tracking system 10 may beused to track one or several targets within the detection area 30,including multiple people 70 and multiple objects 26, 32 alone and inrelation to each other and the amusement park equipment 12. Again, oneor more emitters 14, one or more detectors 16, and one or more controlunits 18 may be utilized in combination with one another and incombination with the control system 142 to perform such tracking. FIG.13 schematically illustrates an overhead view of an embodiment of thedetection area 30 including the floor 92 with an embodiment of the grid90 applied thereon (see, e.g., FIGS. 5 and 7). Specifically, FIG. 13schematically illustrates the manner in which the tracking system 10tracks the position and movement of both machines 170 (objects 26, 32)and people 70 within the detection area 30. The machines 170 may beconsidered to represent a particular embodiment of the amusement parkequipment 12. For clarity, the people 70 are depicted as circles whilethe machines 170 are depicted as polygons.

The tracking schematically illustrated in FIG. 13 may be used in areaswhere the people 70 are expected to interact with or in close proximityto machines 170, such as a warehouse or factory floor, or an amusementattraction with interactive show elements and equipment. For instance,in a parade show, various robots may move about an amusement area, atleast a part of which is the detection area 30. People 70 watching theparade may also be in the detection area 30. Similarly, in a factorysetting, the people 70 may move about the floor 92 while the machines170 are present.

In a typical parade or similar setting, people would remain behind aphysical barrier that blocks the machines 170 and/or the people 70 fromgetting within a certain proximity of one another. However, it is nowrecognized that it may be desirable to remove physical barriers betweenthe people 70 and the moving machinery 170. It is also now recognizedthat a distance barrier may be used to replace a physical barrier toenable the ability for the machines 170 and the control system 142 toreact in time to be as effective as a physical barrier.

It is also now recognized that large physical barriers between machines170 and people 70 can become pinch points for flow (e.g., people and/ormachine traffic). In accordance with an embodiment of the presentdisclosure, the control system 142 may utilize built-in show reasons(e.g., reasons tied to the normal course of an entertainment show) tohave a particular amount of space when the machine 170 is performingquick, complex movements, and then allow contact at other times when themachines 170 are at a resting state.

In an alternative setting, people 70 may work in conjunction withmachines 170 (e.g., robots) in a factory setting to carry out certaintasks. In this case, the detection area 30 would be considered torepresent a factory floor, for example. Typically, machinery and otherequipment would be at least partially controlled by a human operator,for example as a fail-safe. It is now recognized that the presentembodiments may be used to reduce the reliance on human operators tocontrol equipment, which may enhance the efficiency of, for instance,manufacturing processes, inventory processes, and the like.

In the illustrated embodiment, the tracking system 10 is configured totrack movement and position of the people 70 and the machines 170, andfunctions to act as all or a part of a machine guard that keeps themachines 170 from colliding with the people 70 within the detection area30. To act as a machine guard system, the tracking system 10 may beconfigured to determine the presence and track the location of thepeople 70 and the machines 170 on the floor 92, and evaluate theirpositions relative to one another. In the illustrated embodiment, forexample, the detection area 30 includes the grid pattern 90 ofretro-reflective markers 24, as described in detail above with referenceto FIGS. 5 and 7. The control unit 18 may, for example, evaluateocclusion of the retro-reflective markers 24 by comparing reflectivepatterns currently detected to stored patterns to determine whether theocclusion is characteristic of one or a group of the people 70 or ischaracteristic of one or a group of the machines 170. For instance, thecontrol unit 18 may evaluate a geometry of the feature causing occlusionof certain of the retro-reflective markers 24, and determine whether thegeometry correlates more closely to the person 70 or the machine 170 (orgroups thereof).

Although the illustrated embodiment includes the retro-reflectivemarkers 24 disposed in a pattern on the floor 92, other embodiments mayutilize different methods for detecting the presence of the people 70and the machines 170 moving about the floor 92. For example,retro-reflective markers 24 may be disposed on the clothing of thepeople 70 (see, e.g., FIG. 3), or the tracking system 10 may beconfigured to identify and determine the location of the people 70and/or the machines 170 without the use of retro-reflective markers 24at all, as discussed with respect to FIG. 5.

The tracking system 10 may provide control signals to the variousmachines 170 that are operating on the floor based on the detectedpositions and movements of the people 70 on the floor (e.g., based onvector magnitude, vector orientation, and/or vector sense of themovement). As one example, the machines 170 may receive go/no-go signalsfrom the control system 142 (e.g., control unit 18 of the trackingsystem 10). That is, the machines 170 may be operating to move alongcertain predetermined trajectories and perform desired functionsaccording to a preprogrammed routine stored in the memory 162 (see FIG.12). When the tracking system 10 detects a person 70 or another machine170 about to cross the path of one of these machines 170, the trackingsystem may send a “no-go” signal to the machine 170, causing the machine170 to stop its routine and wait until a go signal is provided again(e.g., remain stationary). Once the person 70 is out of the path of themachine 170, the control unit 18 may then send a “go” signal promptingthe machine 170 to continue carrying out its intended operation (e.g.,resume movement). In other embodiments, the machines 170 may receivespecific dynamic instructions from the control system 142 (e.g., controlunit 18) based on the detected positions and movements of the people 70on the floor. For example, the tracking system 10 may prompt themachines 170 to switch from one operation to another or to redirect itstrajectory along the floor 92 in response to the locations of the people70 detected by the tracking system 10.

As also illustrated, certain of the retro-reflective markers 24 may bepositioned on the machines 170 to provide additional trackingfunctionality and information. For example, a combination of gridocclusion information and tracking information relating to the movingretro-reflective markers 24 on the machines 170 may enable greaterdegrees of freedom of movement for the machines 170, as well as greatercontrol over their motion by the control system 142. As one example, theretro-reflective markers 24 on the machines 170 may be configured toreflect the electromagnetic radiation beam 28 (or other electromagneticradiation) back to the detector 16 (or group of detectors 16) at adifferent frequency than that of the retro-reflective markers 24disposed on the floor using different retro-reflective elementsdifferent coatings, etc.

As set forth above with respect to FIG. 12, the tracking system 10 maymonitor the location of people 70 and/or objects 26, 32 relative tocertain attraction equipment 12, and may establish the proximityboundary 152 relative to the attraction equipment 12 that determines,for example, whether certain control actions might need to be performed.As illustrated in FIG. 14, multiple such proximity boundaries,illustrated as boundary regions 180, may be applied by the trackingsystem 10 around one or more of the machines 170 on the floor 92. Theboundary regions 180 may each extend a certain distance away from theouter perimeter of a respective one of the machines 170, which aretracked by the tracking system 10. In accordance with this aspect of thepresent disclosure, it is now recognized that the boundary regions 180may, in certain embodiments, altogether replace physical boundariesbetween people 70 and automated machinery 170 to enhance interactivitybetween the people 70 and the machines 170.

In accordance with certain embodiments, the boundary regions 180 may bedefined relative to the detected locations of the retro-reflectivemarkers 24 positioned on one of the machines 170. That is, for eachmachine 170, one boundary region 180 may be defined relative to theretro-reflective markers 24 positioned on that same machine 170.Additionally or alternatively, the boundary regions 180 may be definedby a distance relative to the detected boundaries of the machine 170,which may be discernable based on occlusion of the grid pattern 90.Indeed, rather than a specific distance as measured in meters, forinstance, the tracking system 10 may define the boundary region 180 asextending from the machines 170 by a certain number of retro-reflectivemarkers 24 of the grid 90.

The tracking system 10 may monitor the boundary region 180 of each ofthe machines 170, and when one of the people 70 or another machine 170crosses into the boundary region 180, the control unit 18 may providecontrol signals to the machine 170 that may instruct the machine 170 toadjust its motion (e.g., stop, redirect). In some embodiments, differentranges, shapes, or distances of the boundary regions 180 extending fromthe machines 170 may be applied to each of the machines 170 located onthe floor 92, for example based on their size, shape, maneuveringcapabilities, and so forth. However, in other embodiments, the samedistance of the boundary regions 180 extending from the machines 170 maybe applied to all of the machines 170 on the floor. In still furtherembodiments, boundary regions 180 may be applied to both the machines170 and to the people 70, such that when the boundary region 180 of oneof the machines 170 intersects the boundary region 180 of one of thepeople 70, the control unit 18 sends control signals to the machine 170to divert or cease the machine's operation (e.g., movement).

As noted above with respect to FIG. 9A, the use of the grid 90 incombination with a single one of the detectors 16 may, in certainembodiments, limit the ability of the tracking system 10 to track andcontrol movement of an object in more than two spatial dimensions.However, using multiple detectors 16 and/or using grids 90 positioned onadditional features (e.g., walls 93), and/or the retro-reflectivemarkers 24 positioned on the machines 170, may enable the trackingsystem 10 to monitor and control the movement of the machines 170 inthree spatial dimensions. For example, in embodiments where the machines170 are capable of moving both in the plane of the floor 92 andcrosswise relative to the plane of the floor 92 (e.g., upward), thetracking system 10 may cause the machines 170 to move within the planeof the floor 92, crosswise relative to the plane of the floor 92, or acombination of these, as appropriate. In this regard, the boundaryregions 180 may be applied not only in directions along the plane of thefloor 92, but also in directions crosswise relative to the floor 92 sothat the tracking system 10 ensures a proper amount of clearance toavoid collisions. As described in further detail below, one such machinecapable of this type of motion may include an unmanned aerial vehicle(UAV) controlled by or otherwise in communication with the controlsystem 142 and the tracking system 10.

FIG. 15 illustrates a method 200 for using the boundary regions 180illustrated and described with reference to FIG. 14. The method 200 mayinclude steps that are stored in the memory 22 and that are executableby one or more processors 20 of the control unit 18. The steps of themethod 200 may be performed in different orders than those shown, oromitted altogether. In addition, some of the blocks illustrated may beperformed in combination with each other. Further, although describedfrom the standpoint of a single one of the machines 170, the method 200may be applied to multiple machines 170 simultaneously.

In the illustrated embodiment, the method 200 includes determining(block 202) a location of the machine 170 based on a position of thereflected electromagnetic radiation received by the detector 16 of thetracking system 10. Again, this position may be determined based on adetection of electromagnetic radiation reflected from retro-reflectivemarkers 24 (disposed on the floor and/or on the machine 170 itself),which includes the absence of such electromagnetic radiation whereexpected. In other embodiments, the control unit 18 may interpret areflection of electromagnetic radiation received via the detector 16 ashaving a profile corresponding to the machine 170.

The method 200 also includes applying (block 204) a boundary (e.g.,boundary region 180) to the machine location (and/or the location of theperson, whichever the case may be). Again, the boundary region 180 maybe applied in two or three spatial dimensions, and may involve not onlyscalar distance information but may, additionally or alternatively,include a number of retro-reflective makers 24 within the grid 90.

The method 200 further includes determining (block 206) a proximity ofthe machine 170 (with the boundary region 180) to other machines 170,people 70, stationary objects, and so forth, and any boundary regionsassociated with those tracked elements. The determination associatedwith block 206 may be performed, for example, by comparing identifiedlocations of the two objects in question to one another, and estimating,modeling, etc., a distance between the two.

In addition, the method 200 includes determining (query 208) whether theidentified proximity is less than or equal to a predetermined thresholdvalue, which may correspond to a distance associated with the boundaryregion 180. Accordingly, this threshold may be the same for all of themachines 170, or the threshold may be different for certain machines170.

If the determined proximity is less than or equal to the thresholddistance, the method 200 includes adjusting (block 210) an operation ofthe machine 170 or redirecting the machine 170. As discussed above, thecontrol unit 18 of the tracking system 10 may send a control signal to acontroller of the machine 170 (e.g., in communication with or associatedwith the actuation system 154 of FIG. 12) to actuate this adjustmentand/or redirection of the machine 170. If the determined proximity isgreater than the threshold, however, no change is made and the method200 repeats.

In some embodiments, there may be degrees of adjustment depending on theproximity determination associated with query 208. For instance, if thevector information associated with movement of the machine 170 suggeststhat the machine 170 has a certain probability of colliding with anotherfeature or person in the detection area 30, the control unit 18 maycause a relatively minor adjustment to some aspect of the machine'smovement that, over time, causes the machine 170 to avoid a collisionwith the other feature or person. In other words, the tracking system 10may be involved in a certain amount of predictive control to mitigatesituations where there is an affirmative answer to query 208. In thisregard, other variations of the method 200 may be used in otherembodiments. For example, in some embodiments, the method 200 may notinclude applying (block 204) the boundary 180 to the machine location,but may instead include estimating an outer edge of the machine 170based on the electromagnetic radiation reflected onto the detector 16,and determining the proximity of this outer edge to other machines 170,people 70, and so forth.

Continuing with the example noted above relating to the movement ofautomated park equipment in a parade context, the tracking system 10 mayalso evaluate information relating to groupings of people 70 relative toindividual machines 170 to enhance interactivity between the people 70and the machines 170 (e.g., by removing physical barriers or reducingreliance on them). More specifically, control system 142, using thetracking system 10, may monitor and control an interactive system wherevariably actuated and controlled embodiments of the amusement parkequipment 12 engages with an audience. The tracking system 10 may beconfigured to provide control signals to the show action equipment 12,which causes actuation of the equipment 12 to engage or interact withthe audience in a relatively efficient and dynamic manner. FIGS. 16 and17 illustrate two instances in which the tracking system 10 may aid incontrolling show action equipment 220 to engage with members of anaudience 222. By way of non-limiting example, the show action equipment220 may include various automated and mobile features such as robots,automatons, and the like. The audience 222 may include any number ofpeople 70 that are standing within close proximity to one another.

As illustrated in FIG. 16, the audience 222 is dispersed throughout thedetection area 30 and does not include a clearly delineable group, forexample as would be expected when seating is available. The dynamic showaction equipment 220 is configured to weave in and out of the audience222, based on tracking performed in accordance with the embodiments setforth above. For instance, the tracking system 10 may identify thelocations of the people 70 in the audience 222 by detecting thereflection of electromagnetic radiation off the people 70 themselves, byevaluating occlusion of the grid 90 on the floor 92, by trackingretro-reflection from retro-reflective markers 24 disposed on thepeople's clothing, or any combination thereof.

Using the detected positions of the people 70, the control system 142(e.g., including tracking system 10) may identify the presence of gaps224 that exist within the audience 222, and evaluate the gaps 224 toenable certain types of movement of the dynamic show action equipment220. Upon identifying the gaps 224 in the audience 222 and anyassociated evaluation thereof (e.g., a comparison of the size of thegaps 224 to the size of the show action equipment 220, likelihood of thegaps 244 changing based on movement vectors of the people 70), thecontrol system 142 (including tracking system 10) may provide controlsignals to the show action equipment 220 that actuate the show actionequipment 220 to move into the gaps 224. As illustrated by arrows 226,the show action equipment 220 may move into the gaps 224 formed withinthe audience 222, and as the people 70 move into different positionsaround the show action equipment 220, the tracking system 10 maycontinue to dynamically determine the locations of gaps 224 in theaudience 222 that the show action equipment 220 can fill. Thus, thecontrol system 142 controls the show action equipment 220 to move in andout of open spaces, making the show action equipment 220 dynamicallyadapt to the audience 222.

In FIG. 17, the dynamic show action equipment 220 is configured totarget, for enhanced interaction, a particular group 230 of people 70.According to the techniques disclosed above, the control system 142(including tracking system 10) may identify the locations of the people70 that are present in the detection area 30, by detecting thereflection of electromagnetic radiation off the people 70 themselves oroff of retro-reflective markers 24 disposed in a pattern along the floorwhere the crowd people 70 are standing. Based on the detected positionsof the people 70, the control system 142 (including tracking system 10)may detect the groups 230 of people 70 present within the area 30. Thatis, the control system 142 may determine, based on the locations of thepeople 70, where the people 70 are more densely gathered into groups 230along the detection area 30. Upon identifying the groups 230, thecontrol system 142 may provide control signals to the show actionequipment 220 that actuate the show action equipment 220 to move intorelatively close proximity to the groups 230. In some embodiments, theshow action equipment 220 that is initially positioned away from thegroups 230 may be actuated to move toward one of the identified groups230, as illustrated by an arrow 232. In other embodiments, the controlsystem 142 may send signals to the show action equipment 220 that ispositioned nearby the identified groups 230 to trigger an effect via theshow action equipment 220. When different pieces of the show actionequipment 220 are positioned in certain orientations relative to oneanother, other actions (e.g., interactions between the pieces, effects,or stoppage) may be initiated.

It should be noted that in either form of dynamic show action equipmentinteraction with people 70, as illustrated in FIGS. 16 and 17, the showaction equipment 220 may be controlled to maintain a desired thresholddistance from the people 70 or other show action equipment 220 withinthe detection area 30. Specifically, the control system 142 may utilizea control scheme similar to that discussed above with reference to themethod 200, for example to maintain a spatial barrier rather than aphysical barrier around each piece of show action equipment 220. In someembodiments, a physical barrier may not be eliminated but may be lessrestrictive, allowing more enhanced interaction between the people 70and the equipment 220.

The enhanced interactivity afforded by embodiments of the disclosedtracking system 10 is not necessarily limited to the context of movingvehicles or similar equipment through a crowd of people. Indeed, thetracking system 10 may be used, in some embodiments, to provide feedbackfor evaluating animation quality of an animated figure, such as anautomaton having human-like features. Other embodiments of an animatedfigure may include a robotic dog, cat, or other living organism whosemovement may be mimicked using robotics. FIG. 18 illustrates anembodiment of an automaton 250 equipped with a plurality of theretro-reflective markers 24, each marker 24 of the plurality beingplaced at strategic points along the automaton 250 (e.g., top and bottomof the head, shoulders, elbows, and wrists). The placement of theretro-reflective markers 24 may enable tracking of the automaton'smovements. As all or a portion of the automaton 250 moves through spaceand time, one or more of the emitters 14 may emit the electromagneticradiation beam 28 toward the automaton 250, and one or more detectors 16may detect the reflection of the electromagnetic radiation beam 28 offthe retro-reflective markers 24. Based on data received from the one ormore detectors 16, the control unit 18 may determine the approximatepositions of the various limbs of the automaton 250, and compare theseapproximate positions to expected positions stored in the memory 22.Thus, the control unit 18 may determine whether the limbs of theautomaton 250 are operating within predetermined constraints. Feedback252 based on this analysis, or representative of raw or minimallyprocessed data, may be provided from the control unit 18 to otheramusement park processing and control features, such as animationcontrol circuitry 254. Again, similar techniques may be applied to anydesirable animated figure, not just one representative of a human. Itshould be noted that automatons 250 and other such moving equipment maybe calibrated using techniques in accordance with present embodimentsto, for example, provide consistently realistic motion. For example, theautomatons 250 may be tracked according to the present techniques andmatched to a movement template associated with realistic motion. Thecontrol unit 18 may perform re-calibration of the automatons 250 withinthe amusement park on a periodic basis according to the movementtemplate by tracking movement of the retro-reflective markers 24positioned on the automatons 250, and adjusting the movement of theautomatons 250 so that the movements of the markers 24 substantiallycorrespond with the movement template. Such calibration may beperformed, for example, when no objects or people are expected to belocated proximate or within view of the automatons 250.

The control of machines in the manner set forth above may also beapplied to amusement park equipment 12 capable of moving throughout anamusement park 268, as illustrated in the overhead view of FIG. 19.Indeed, as illustrated in FIG. 19, it is now recognized that thedisclosed tracking system 10 may be used in conjunction with, forexample, an unmanned aerial system (UAS) 270 to track the location andmovement of one or more unmanned aerial vehicles (UAVs) 272 to, forexample, provide all or a part of a light show, to enhance a themedshow, to support special effects, for monitoring, to interact withpeople, to broadcast a wireless (e.g., WiFi) signal, and similarfunctions within the amusement park 268.

More specifically, FIG. 19 depicts an example layout of the amusementpark 268 in which one or more UAVs 272 may be tracked in three spatialdimensions and in time using the disclosed tracking system 10. Inaccordance with certain embodiments, the tracking system 10 may trackretro-reflective markers 24 positioned on (e.g., fixed on) the UAVs 272.The presence of multiple retro-reflective markers 24 on the UAVs 272 mayenable the detector 16 to compare the electromagnetic signals that areretro-reflected from the different markers 24 to determine a location,orientation, velocity, etc., of each of the UAVs 272 in accordance withthe embodiments discussed above with respect to FIG. 9A. As shown, theUAVs 272 each include three retro-reflective markers 24, though fewer ormore retro-reflective markers 24 may be used depending on the trackingbeing performed by the tracking system 10 and the expected manner ofmovement of the UAVs 272.

Tracking the UAVs 272 in accordance with present embodiments may alsoenable automated control over their movement, for example by providingtracking information generated by the tracking system 10 as feedback forUAV control circuitry 274 associated with the control system 142. Forinstance, the UAV control circuitry 274 may be one or more sets ofinstructions stored on a memory of the control system 142 (e.g., asoftware package), such as memory 22 of the control unit 18, or mayinclude one or more application specific integrated circuits (ASICs),one or more field programmable gate arrays (FPGAs), one or more generalpurpose processors, or any combination thereof. The UAV controlcircuitry 274 may also include communication devices configured tocommunicate with the UAVs 272, though it is presently contemplated thatthe UAVS 272 may utilize communication techniques shared by the trackingsystem 10 to facilitate processing and control of UAV positions,velocities, etc.

One or more of the tracking systems 10 may be positioned within theamusement park 268. Indeed, as set forth above, the use of multipledetection devices enables enhanced tracking capabilities, especiallywhere the tracked target is expected to have several degrees of movementfreedom. Accordingly, the amusement park 268 will generally at leastinclude multiple detectors 16 so that the tracking system 10 is capableof obtaining signals from at least one of the retro-reflective markers24 on the UAV 272 at any given time, regardless of the orientation ofthe UAV 272 relative to the ground. As illustrated, the UAVs 272 maymove along a guest pathway 276, which people 70 may use to travel onfoot (or on a conveyance) between certain attractions (e.g., buildings278). Elements of the tracking system 10 may be positioned on some orall of the buildings 278, for example on portions of the buildings 278that face toward the guest pathway 276. This may enable the emitters 14to have overlapping electromagnetic emissions (e.g., light beams 28) sothat the retro-reflective markers 24 are illuminated substantiallycontinuously, thereby enabling the detectors 16 associated with theemitters 14 to have a substantially continuous view of the travellingUAVs 272. The emitter 14 and detectors 16 may, alternatively oradditionally, be positioned on other environmental objects in theamusement park 268 or on their own support. For example, as shown inFIG. 19, one or more of the emitters 14 and one or more of the detectors16 may be fixed to a post 280 positioned proximate the pathway 276 in amanner that enables the emitter 14 to emit the electromagnetic radiationbeam 28 into or above the pathway 276 and the detector 16 to receiveretro-reflected light from retro-reflective elements on the pathway 276or on the UAVs 272.

The amusement park 268 may use a single one of the control units 18 thatcommunicates (e.g., wirelessly) with several (e.g., some or all) of theemitters 14 and the detectors 16 positioned along the pathway 276, ormay use several control units 18 as illustrated. As the UAVs 272 travelalong the pathway 276, which may represent the detection area 30 ofseveral of the tracking systems 10, they may travel through and beyondthe detection areas 30 of each emitter/detector pair. Accordingly, thecontrol system 142 may coordinate the hand-off between signals from onedetector 16 to another detector 16 as the UAVs 272 travel along thepathway 276 to enable substantially continuous tracking of each UAV 272.Such hand-offs may also occur between control units 18 of the trackingsystems 10. That is, as one tracking system 10 ceases to track one ofthe UAVs 272 because the UAV 272 has moved out of the detection area 30associated with its emitters 14 and detectors 16, it may hand off thetracking of that UAV 272 to another tracking system 10 that ispositioned along the predicted path of the UAV 272 (e.g., based onvector orientation and sense of the UAV's movement).

The tracking system 10 may also track occlusion of the grid 90 ofretro-reflective markers 24 on the pathway 276, which may correspond tothe floor 92 described above with respect to the tracking of people 70and machines 170 in an area. Indeed, the tracking system 10 may beconfigured to track the presence and location of people 70, such as agroup of people 70, along the pathway 276. Tracking the people 70 alongthe pathway 276 may be desirable for a number of reasons, for example toenable the UAV 272 to avoid collisions with the people 70 and to enableenhanced interactions with the people 70. Further, the tracking systems10 may also use occlusion of the grid 90 as part of an overall trackingmethod used to track the UAVs 272. For example, one or more of thedetectors 16 may have an overhead view of the pathway 276 and the UAVs272 such that the UAVs 272 are positioned between the grid 90 and thedetectors 16. Accordingly, in some embodiments, the tracking systems 10may correlate certain patterns of grid occlusion to the UAVs 272.

The tracking system 10 may also, for example using the grid 90,associate a boundary 282 with groups of the people 70 to enable thetracking system and the UAV control system 274 to maintain the UAVs 272a certain distance away from the people 70. The tracking system 10 mayalso monitor certain areas where the people 70 are expected to gather orgroup, such as a guest seating area 284, and may apply a boundary 286 tothe same so that the UAV 272 maintains a certain distance away from theseating area 284.

In this regard, the UAV control system 274 may be configured to adjust aflight path of the UAVs 272 for a number of reasons, includingapproaching the boundaries 282, 286, or when the UAV control system 274evaluates certain diagnostic information associated with the UAVs 272and determines that one of the UAVs 272 is in need of maintenance.

To enable the enhanced interactions, flight path adjustments, and otheraspects noted above relating to the UAVs 272, each of the UAVs 272 mayhave a variety of components 288, which may include various electricaland electromechanical systems, among others. As illustrated, in ageneral sense, the UAVs 272 may include a movement control system 290,which includes various electromechanical devices such as helicopter-likeblades, various pumps associated with a propulsion system, or similardevices. In embodiments where the UAVs 272 uses a propulsion system, thepropulsion system may use a compressed gas and/or a combustible fuel andoxidant. A lift system associated with the UAVs 272 might also include apropulsion-based lift system, or may use rotating blades to create liftas is done in a helicopter, or a combination of these features.

The components 288 may also include various interactive features 292,which enable enhanced interactions with the people 70, coordination ofshow effects and/or special effects with a show performed within, forexample, a show area 294. By way of non-limiting example, theinteractive features may include audio transducers such as speakers, ormicrophones, may include various electromagnetic radiation sources, suchas lasers, light emitting diodes (LEDs), strobe lights, and so forth.Additionally or alternatively, the interactive features 292 may includeother emitters that provide a discernable stimulus to the people 70,such as scent emitters configured to emit certain chemicals associatedwith certain types of scents, compressed gas emitters to emit bursts ofcompressed air for tactile stimulation, and so forth.

To enable the UAVs 272 to be controlled by the UAV control system 274,and in some embodiments to enable redundant tracking of the UAVs 272,the components 288 may also include a communication system 296. Thecommunication system 296 may include various communication devices suchas Wi-Fi transceivers, radiofrequency communication devices, or anyother device capable of communication via certain bands of theelectromagnetic spectrum. The communication system 296 may enable theUAVs 272 to communicate with the UAV control system 274, and vice-versa,to enable the UAV control system 274 to initiate adjustments of positionusing the movement control system 290, to cause the UAVs to trigger oneor more show effects or other interactive elements using the interactivefeatures 292, and so forth.

Having described various features of the UAVs 272 and the amusement park268, various aspects relating to the operation of the UAVs 272 will bedescribed in further detail herein to provide a better understanding ofcertain aspects of the present embodiments. For example, as the UAVs 272travel along the pathway 276, they may be tracked by the trackingsystems 10, based on their associated retro-reflective markers 24 and/orbased on grid occlusion as described above. As the UAV 272 encountersobjects or people, as shown by the group of people 70 proximate one ofthe buildings 278, the tracking system 10 may recognize that the UAV 272has a trajectory that could potentially cause the UAV 272 to interferewith the people 70. Accordingly, the UAV control system 274 maycommunicate with the UAV 272 to instruct the UAV 272 to change itsflight path around the boundary 282 associated with the group of people70. The adjusted flight path of the UAV 272 is shown generally as anarrow 298.

The tracking systems 10 may also be used to maintain the UAVs 272 withincertain areas of the amusement park 268. For example, the trackingsystem 10 may track the retro-reflective markers 24 on the UAV 272relative to a known boundary 300, which may be considered to representan area not in view of one or more of the tracking systems 10.Accordingly, if the tracking system 10 determines that the UAV 272 hasgone outside or beyond the known boundary 300, the UAV control system274 may send control signals to the UAV 272 that causes the UAV 272 tostop or to be directed to different areas. Similarly, the UAV 272 mayinclude on-bard features that perform this operation, as described infurther detail below.

As shown, the UAV 272 may be directed along a number of differentpathways, which are depicted as dashed arrows leading to differentenvironmental features of the amusement park 268. For example, the UAV272 may be directed by the UAV control system 274 along a first path 302to a stop area 304. The stop area 304 is generally intended to representan area of the amusement park 268 that is away from areas where people70 may be located, and/or away from where show attractions are located.In this way, the stop area 304 may also be intended to represent anemergency stop location.

The UAV 272 may be directed to the stop area 304 for a number ofreasons. As one example, the UAV control system 274 may determine thatthe UAV 272, based on diagnostic information, requires repairs or is inneed of maintenance. In these situations, the UAV 272 may be directedalong the first path 302 to the stop area 304, which may be accessibleto various technicians or other operators that can then repair the UAVs272. Alternatively, the UAV 272 may include its own flight pathadjustment instructions, which may be carried out by the movementcontrol system 290 in certain situations. For instance, if thecommunication system 296 of the UAV 272 loses connection with thecontrol system 274, the UAV 272 may direct itself to the nearest regionthat is considered to be away from guests and show attractions, in thiscase the stop area 304.

In other embodiments, the UAV 272 may be directed along a second pathway306 back toward the guest pathway 276. For example, the UAV 272 maybegin to travel along the first path 302 and, in response to certainupdated instructions by the UAV control system 274, change itsdestination. For example, if the control system 274 determines that theUAV 272 is needed to assist in a show, the UAV control system 274 maysend appropriate instructions to the UAV 272 to diverge from the firstpath 302 to the second path 306 and toward the guest pathway 276, whichmay lead to the show area 294. Accordingly, the UAV control system 274may make real-time adjustments to the various flight paths of the UAV272 as needed.

As still another example of the divergent flight paths, the UAV 272 maybe diverted from the first path 302 to a third path 308 that leads toone of the buildings 278. Such a flight path adjustment may be made bythe UAV control system 274 in response to an indication that the UAV 272is out of a particular range of communication or out of a range of oneor more of the tracking systems 10.

Accordingly, the UAV control system 274, in a general sense, may sendsignals to the UAV 272 that cause the UAV 272 to return to a particularregion of the amusement park 268 to re-establish tracking by thetracking system 10. Further still, the UAV 272 may have automatedroutines that are carried out when certain connections are terminatedbetween the UAV 272 and the UAV control system 274. In such an instance,the UAV 272 may follow an adjusted flight path, such as illustrated bythird flight path 308, which directs the UAV 272 to a known location orlocation having a particular type of beacon recognizable bycommunication system 296 of the UAV 222.

The UAV control system 274 may also engage, in combination with one ormore of the tracking systems 10 positioned at the show area 294, incoordinating actions of the UAV 272 with performers 310 in the show area294. For example, the UAV control system 274, upon receipt of trackinginformation from the tracking system 10, may coordinate the movement ofthe UAV 272 with tracked movement of the performers 310 and/or any otherobjects within the show area 294. Further still, the UAVs 272 mayprovide enhanced interactivity with the guests in the guest seating 284by moving from the show area 294, within the boundary 286 of the guestseating 284, and back. In situations where the UAV control system 274determines that the UAV is not performing as intended or is beginning todrift out of a tracked location, or any other undesirable circumstance,the UAV control system 274 may direct the UAV 272 into one of aplurality of stop areas 312 and initiate a stop of the UAV 272. Withinthe stop areas 312, the initiated stop of the UAV 272 may cause the UAV272 to shut down. As one example, the stop areas 312 may be islandssurrounded by a body of water, or individual bodies of water, where nopeople 70 or other show objects are expected to be located.

Example configurations of the UAV 272 may be further appreciated withrespect to FIGS. 20 and 21, which are bottom and elevational views,respectively, of different embodiments of the UAVs 272. Specifically,the bottom view of the embodiments of the UAV 272 illustrated in FIG. 20depicts the UAV 272 as a quad copter having a plurality of lift and/orpropulsion devices 320. The lift and/or propulsion devices 320 areattached to a body 322 of the UAV 272 via arms 324. However, it shouldbe noted that the illustrated embodiment of the UAV 272 is but oneexample, and other configurations are also within the scope of thepresent disclosure. As depicted, the body 322 and the arms 324 may befitted with one or more of the retro-reflective markers 24. Accordingly,the tracking system 10 may be configured to track three-dimensionalspatial movement of the UAV 272 in time. For example, the UAV 272 mayhave at least one, at least two, or at least three of theretro-reflective markers 24. It is recognized that including several ofthe retro-reflective markers 24 may enable the tracking system 10 totrack the UAVs 272 with a higher degree of precision and accuracy,including tracking an orientation of the UAV 272 based on relativeperspective positioning of the retro-reflective markers 24. For example,the orientation of the UAV 272 may be tracked according to thetechniques described above with respect to FIGS. 9B and 9C.

It should also be noted that the positioning of the retro-reflectivemarkers on the UAV 272 (e.g. on the body 322 and/or the arms 324) mayprovide the tracking system 10 the ability to track a roll, a pitch, anda yaw of the UAV 272. This tracking may be useful for adjusting orotherwise controlling the flight path of the UAV 272 by, for example,the control unit 18 and/or the UAV control system 274.

The illustrated embodiment of the UAV 272 also includes specificexamples of the components 288. The components 288, as shown, mayinclude a speaker 326 that is part of the interactive features 292depicted in FIG. 19, and the emitter 328 that is also part of theinteractive features 292 in FIG. 19, lift and/or propulsion controlcircuitry 330, which may be a part of the movement control system 290 ofFIG. 19, and a transceiver 332, which may be a part of the communicationsystem 296 depicted in FIG. 19. The components 288 may also includeprocessing circuitry including one or more processors 334 and one ormore memory 336 for performing various analysis and control routinesrelating to the operation or information received from any one orcombination of the components 288.

Moving now to the embodiment of the UAV 272 depicted in FIG. 21, asshown, the UAV 272 may include all or part of a tracking system 10configured in accordance with present embodiments. For instance, the UAV272 may incorporate at least one of the emitters 14 and at least one ofthe detectors 16 via attachment to the body 322, for example on adownward facing surface 350 of the body 322. The use of the trackingsystem 10 on the UAV 272 may be desirable, for example, to enable theUAV 272 to navigate through or otherwise follow a path ofretro-reflective markers 24 disposed on, for instance, the pathway 276.Accordingly, the UAV 272 may be configured to at least partially movethrough the amusement park 268 using only instructions and tracking thatare contained on or within the UAV 272. However, the present disclosurealso includes embodiments in which the communication system 296 of theUAV 272 receives instructions from the UAV control system 274 (e.g. toupdate a destination), and the UAV 272 follows retro-reflective markers24 to a particular destination. Accordingly, it should be appreciatedthat certain of the retro-reflective markers 24 forming a path may havedifferent optical qualities that enable paths to be differentiated fromone another. Furthermore, the UAV 272 may include the emitter 14 and thedetector 16 and utilize them to track other devices or to track peopleusing any one or a combination of the techniques described above.

The overall structure of the UAV 272 may also be further appreciatedwith respect to the illustration in FIG. 21. As illustrated, the UAV 272includes a top surface 352, which may serve as a ledge or platformconfigured to carry certain of the special effect devices or equipmentconstituting all or part of the interactive features 292. Indeed, thefeatures integrated onto the UAV 272 may be positioned on the topsurface 352, on the downward facing part 350, or anywhere else on theUAV 272.

As set forth above, several different types of equipment, machinery,vehicles, etc., may be tracked in accordance with present embodimentsusing the tracking system 10. Indeed, in addition to tracking robots,UAVs, and so forth, the present embodiments may utilize the trackingsystem 10 to track the movement of a ride vehicle in space and time,either along a physically constrained path (e.g., a track or railsystem) or along an unconstrained path (e.g., a path defined byenvironmental features). FIGS. 22-25 depict embodiments where a ridevehicle 360 (or multiple such vehicles 360) is positioned on aconstrained path 362 and is tracked using the tracking system 10, whileFIGS. 26-29 depict embodiments where ride vehicles 360 are positioned onan unconstrained path 363 and are tracked using the tracking system 10.The tracking may generally be performed in accordance with any one or acombination of the embodiments set forth above with respect to FIGS. 3-9depending, for example, on whether the tracking will be fortwo-dimensional motion or three-dimensional motion.

In evaluating the operation of an amusement park attraction, it may bedesirable to track the location of the ride vehicle 360 in space, inorder to ensure that the ride vehicle 360 is moving and operating asexpected. If the ride vehicle 360 is not at the desired position ororientation at a certain time, this may indicate that the ride vehicle360 is not operating as desired and, thus, may benefit from preventativemaintenance.

Starting first with tracking the ride vehicles 360 from an overheadperspective, and in two dimensions, FIG. 22 illustrates an embodimentwhere different ride vehicles 360 on the track 362, together forming aamusement attraction 364, each feature one of the retro-reflectivemarkers 24A, 24B, 24C, and 24D. The markers 24A, 24B, 24C, and 24D areeach configured to retro-reflect a different frequency of theelectromagnetic radiation (e.g., electromagnetic radiation beam 28) backto the detector 16. The tracking system 10 may track theretro-reflective markers 24A, 24B, 24C, and 24D to distinguish theparticular ride vehicles 360 from one another and to detect theapproximate location of each of the ride vehicles 360, either relativeto a coordinate frame or relative to each other, or both.

For instance, in some embodiments, the different ride vehicles 360 maybe associated with different instructions or location information storedin the control unit 18 of the tracking system 10. In this example, thecontrol unit 18 may be configured to send a control signal configured tocause actuation of certain of the amusement park equipment 12 when oneof the ride vehicles 360 passes a certain point on the track 362. Thecontrol unit 18 may identify this ride vehicle 360 based on thefrequency of electromagnetic radiation reflected by the retro-reflectivemarker 24 associated with the particular ride vehicle 360, thustriggering the amusement park equipment (e.g., an effect device) whenthe ride vehicle 360 passes the point on the track 362. In otherembodiments, the particular qualities of the electromagnetic radiation(e.g., particular frequency, phase, wavelength) retro-reflected back bya particular retro-reflective marker 24 (e.g., 24A, 24B, 24C, or 24D)may signal the control unit 18 to utilize a different algorithm storedin the memory 22 (e.g., associate the ride vehicle 360 and its markerwith a different effect device or different control parameters). Itshould be recognized that other types of systems and applications mayutilize the tracking system 10 having the control unit 18 coded tofollow a first set of instructions when the reflected electromagneticradiation from the retro-reflective marker 24 is, for example, at afirst frequency and to follow a second set of instructions when theelectromagnetic radiation from the retro-reflective marker 24 is, forexample, at a second frequency.

As also set forth above, for example with respect to FIG. 9A, multipleseparate detectors 16 may be utilized to each detect retro-reflectivemarkers 24 from different perspectives and/or to track a differentfrequency of electromagnetic radiation reflected by the retro-reflectivemarkers 24. FIG. 23 illustrates one such embodiment of the trackingsystem 10 used to track the ride vehicle 360 in three dimensional space.Specifically, the tracking system 10 includes two sets of emitters 14and detectors 16, illustrated as a first set 370 and a second set 372.

The first emitter/detector set 370 is disposed above the amusementattraction 364, and the second emitter/detector set 372 is disposed tothe side of the amusement attraction 364. Thus, the first set 370 isconfigured to obtain an overhead (e.g., plan) view, while the second set372 is configured to obtain an elevational view of the ride vehicle 360.Specifically, in the illustrated embodiment, the first set 370 isdisposed such that the emitter 14 and the detector 16 are aligned with aplane formed by an X axis 374 and a Y axis 376 of the amusementattraction 364. In addition, the second set 372 is disposed such thatthe emitter 14 and the detector 16 are aligned with a plane formed bythe X axis 374 and a Z axis 378. This way, the first set 370 may trackthe position of the ride vehicle 360 along the X-Y plane, while thesecond set 372 may track the position of the ride vehicle 360 along theX-Z plane, which is orthogonal to the X-Y plane. This may provide arelatively accurate approximation of the three dimensional positionand/or orientation of the ride vehicle 360. In embodiments where theride vehicle 360 operates in only a single plane (e.g., X-Y plane), onlyone of the sets 370, 372 of the emitter 14 and detector 16 may be usedto track the two dimensional position of the ride vehicle 360.Alternatively, redundant sets of emitters 14 and detectors 16 may beutilized (e.g., to provide range).

Moving now to FIG. 24, an embodiment of the amusement attraction 364 inwhich the track 362 is positioned indoors or proximate to a structurehaving a support mechanism for the tracking system 10 is illustrated.More specifically, FIG. 24 depicts the manner in which the track 362 mayinclude complex turns, and how the tracking systems 10 of the presentdisclosure may be used to track movement of the ride vehicles 360 alongthe track 362.

The tracking system 10 may include one or more emitters 14 configured toemit the light beams 28 and detectors 16 configured to detect theelectromagnetic radiation reflected from objects in the detector's fieldof view. In the illustrated embodiment, the emitters 14 and detectors 16are positioned on a ceiling 380 of the amusement attraction 364. Inother embodiments, however, the emitters 14 and detectors 16 may bepositioned along other stationary components of the amusement attraction364 facing toward the track 362. The ride vehicles 360 may each includeretro-reflective markers 24 on their outer surfaces 382. In thiscontext, the tracking system 10 may be used to determine and keep anaccurate count of the number of ride vehicles 360 present on theparticular amusement attraction 364, and tie tracking information to theparticular ride vehicles 360 (e.g., when the ride vehicles 360 includeretro-reflective markers 24 with different optical qualities).

The multiple emitters 14 and detectors 16 may provide redundancy whilemonitoring the ride vehicles 360 as they travel along the track 362.Some detectors 16 may be better positioned than others to detectelectromagnetic radiation retro-reflected from certain areas of theamusement attraction 364. In some embodiments, the multiple emitters 14and detectors 16 may be disposed at different angles throughout theamusement attraction 364 to provide a redundant and, therefore, moreaccurate tracking of the various retro-reflective markers 24 disposedwithin the amusement attraction 364. The multiple sets of emitters 14and detectors 16 may be communicatively coupled to the same control unit18, or different control units 18, for comparing the results from thedifferent detectors 16. However, it should be noted that singledetectors 16 may also be used to track three-dimensional orientation ofthe ride vehicles 360, for example according to the techniques describedabove with respect to FIGS. 9B and 9C.

As illustrated, the track 362 may include a series of complex curvaturesthat may otherwise be difficult to track using existing trackingtechnologies, such as linear encoders. However, in accordance withpresent embodiments, the track 362 may include a plurality of theretro-reflective markers 24 positioned thereon, and the tracking system10 (including multiple emitters 14 and detectors 16) may track andevaluate occlusion of these retro-reflective markers 24 to evaluate theperformance of the ride vehicles 360 on the track 362.

The illustrated amusement attraction 364 also includes a ride controlsystem 382 in communication with the control unit 18, and the ridecontrol system 382 includes control circuitry 384 configured to adjustvarious operational parameters of one or more of the ride vehicles 360.Specifically, the control circuitry of the ride control system 382 mayinclude actuation control circuitry 386 and braking control circuitry388. The actuation control circuitry 386 may be implemented as softwarecode stored in memory and executed by one or more processors associatedwithin the control system 142 of the amusement park, or may beimplemented as control logic circuits that are local to the amusementattraction 364.

In accordance with present embodiments, the amusement attraction 364includes these features described above to enable the control unit 18and the ride control system 382 to monitor the operation of the ridevehicles 360 as they move along the track 362. The control unit 18 andride control system 382 may also, as appropriate, adjust speed, braking,or other operational parameters associated with the ride vehicles 360 asa result of the monitoring performed by the tracking system 10.

As illustrated, the track 362 includes the complex curvatures notedabove, specifically a hill 390, a curve 392, and a combination of a hilland a curve, denoted as a curved hill or curved slope 394. Again, it maybe difficult for traditional tracking features, such as linear encoders,to track movement along the track 362. Indeed, these traditionaltracking features are typically used for tracking motion along straightlines. Accordingly, it is now recognized that the use of theretro-reflective markers 24 positioned along the track 362 may provideenhanced tracking of the movement of the ride vehicles 360 along thetrack 362.

As an example of the operation of the amusement attraction 364 and itsassociated tracking system 10 and ride control system 362, the emitters14 and the detectors 16 may operate to detect reflected electromagneticradiation from the markers 24 positioned on the track 362 and on theride vehicles 360, where present. When the ride vehicles move along thetrack 362, the ride vehicles 360 occlude certain of the retro-reflectivemarkers 24 disposed along the track 362. In certain embodiments, whenthe ride vehicle 360 is operating properly, the retro-reflective markers24 occluded by the ride vehicles 360 may not be visible to any of thedetectors 16. However, in embodiments where the ride vehicles 360slightly lift away from the track 362 (e.g., at high speeds and tightturns), all or a portion of one or more retro-reflective markers 24 thatshould be occluded by the ride vehicle 360 may be visible to at leastone of the detectors 16, which may receive retro-reflectedelectromagnetic radiation from the un-occluded marker 24. In thisinstance, the tracking system 10, and more specifically the control unit18, may identify a pattern associated with this type of situation, whichmay be further appreciated with reference to the illustration in FIG.25.

Specifically, FIG. 25 depicts an overhead view of the track 362 in FIG.24. As shown, a leftmost ride vehicle illustrated with dashed lines 360Amay occlude certain of the retro-reflective markers 24, which isillustrated as a 3 by 3 pattern of occluded retro-reflective markers(i.e., a pattern in which three adjacent markers are occluded in tworows). As may be appreciated from the illustration, un-occluded orvisible retro-reflective markers 24 are depicted as solid/filledcircles, while occluded retro-reflective markers 24 are depicted asun-filled circles. A second of the ride vehicles 360B is alsoillustrated as occluding all retro-reflective markers 24 on the track362 corresponding to the geometry of the ride vehicle 360. Accordingly,the tracking unit 18 may determine that the ride vehicle 360 is movingappropriately (e.g., an appropriate speed) along the track 262.

On the other hand, the complex curve associated with the curved slope394 may at times be difficult for ride vehicles 360 moving at arelatively fast velocity to properly navigate. Thus, as shown, a thirdof the ride vehicles 360C is depicted as occluding only some of theretro-reflective markers 24 corresponding to its geometry. This is shownin FIG. 25 as a 2 by 3 set of occluded retro-reflective markers 24(i.e., a first row of two adjacent occluded markers across from a secondrow of three adjacent occluded markers), with one of theretro-reflective markers 24A being shown as not occluded or not fullyoccluded based on the view of one or more of the detectors 16. Thetracking unit 18 may process this tracking data and determine that thespeed of the ride vehicle 360 was too high going in to the curved slope394, and may adjust, via the ride control system 382, a speed of theride vehicle 360. In embodiments where the tracking unit 18 and/or theride control system 382 and/or the control system 142 determines thatsuch speed adjustments do not have an effect on the occlusion of theretro-reflective marker 24A, the tracking unit 18 and/or the ridecontrol system 382 and/or the control system 142 may determine that theride vehicle 360 is in need of maintenance, or that the track 362 mayneed to be adjusted.

Moving now to embodiments where the ride path for the ride vehicles 360is not constrained by the track 362, the illustrated embodiment of theamusement attraction 364 in FIG. 26 includes the unconstrained ride path363, as noted above. The unconstrained ride path 363 may be consideredto be unconstrained because the path 363 is constrained only byenvironmental elements bounding the path through which the ride vehicles360 may travel (not by engagement between wheel assemblies and rails,such as on a typical roller coaster). As with certain of the embodimentsset forth above, the emitters 14 and the detectors 16 may be positionedon a variety of different environmental features of the amusementattraction 364. For example, as illustrated, the emitters 14 and thedetectors 16 may be positioned on buildings 278, posts 280, or similarstructures enabling a view of the path 363.

As shown, the tracking system 10 may be more intimately involved in themotion of the ride vehicles 360 compared to the embodiments set forthabove with respect to FIGS. 22-25. That is, the ride vehicles 360 shownin FIG. 26 may be controlled in substantially real-time by the ridecontrol system 382. More specifically, ride control system 382 mayinclude communication circuitry 400 such as a transceiver configured tocommunicate with respective control units 402 of the ride vehicles 360.As illustrated, the respective control circuitry 402 of the ridevehicles 360 may include communication circuitry 404 such as atransceiver, one or more processors 406 and one or more memory 408,which are configured to execute various control routines in response toinstructions received from the ride control system 382. For instance,the control circuitry 402 of the ride vehicles 360 may be configured toadjust speed and/or direction of the ride vehicles along the path 363.

The instructions provided to the control circuitry 402 by the ridecontrol system 382 may depend on tracking information provided by one ormore control units 18 associated with the one or more tracking systems10 disposed throughout the amusement attraction 364. For instance, theride control system 382 may, upon receipt of tracking information,perform various routines stored on memory 410 using one or moreassociated processors 412 to adjust the operation of one or more of theride vehicles 360.

The tracking information provided by the tracking systems 10 disposedthroughout the attraction area may include, by way of example,information relating to retro-reflective markers 24 positioned on anoutside of the ride vehicles 360 and/or retro-reflective paint used asretro-reflective markers 24 on the vehicle 360. The tracking informationmay be as generally set forth above with respect to FIGS. 3-9, where thetracking systems 10 use one or more of the detectors 16 to track theride vehicles 360 in space and time in two dimensions or threedimensions as appropriate. Because the ride path 363 is unconstrained,it may be desirable to track the ride vehicles 360 in space and time inthree spatial dimensions.

In accordance with certain embodiments of the present disclosure, thetracking system 10 and the ride control system 382 may coordinate toperform block control, where the path 363 is divided into blocks orzones in which a predetermined number of ride vehicles 360 are allowed(e.g., by way of rules stored in memory 22) to occupy a particularblock. Accordingly, the path 363 is illustrated by way of example asincluding a plurality of such blocks, including a first block 414associated with loading of an empty ride vehicle 416 (e.g., associatedwith a loading area 418 of the amusement attraction 364 where people 70are queued behind an entrance 420). The plurality of blocks alsoincludes a second block 422 and a third block 424 separated from eachother, and other blocks, by retro-reflective boundary lines 426. Thetracking system 10 may be configured to track occlusion of the boundarylines 426 to determine whether ride vehicles 360 have crossed betweencertain of the blocks to determine if an appropriate number of vehicles360 are positioned within each of the blocks. Additionally oralternatively, the tracking system 10 may monitor a position of each ofthe vehicles 360 via retro-reflective makers 24 positioned on thevehicles 360 relative to the boundary lines 426. If the tracking system10 determines that there are too many vehicles 360 present withincertain blocks, or in close proximity thereto, the tracking system 10may cause certain of the vehicles 360 to stop until the vehicles 360 inthat particular block have cleared. In other embodiments, the ridecontrol system 382 may initiate actuation of a feature that causesadditional pathways to be opened to certain of the vehicles 360. Indeed,such block control may be applied not only to an unconstrained path 363,but also to the constrained path 362 as described above.

Continuing with the embodiment illustrated in FIG. 26, the path 363 mayinclude an embodiment of the grid 90 within a fourth block 428 to enablethe tracking system 10 to monitor occlusion of the markers 24 and trackpositions and movement of the vehicles 360. The tracking system 10 may,in certain embodiments, apply a boundary to each of the vehicles 360 inthe fourth block 428 (or any other block) to maintain a certain distancebetween the vehicles 360 to avoid collisions and maintain a substantialmovement of the vehicles 360 along the path, for example as set forthabove with respect to FIGS. 13-17. Further, the tracking system 10 mayutilize the grid 90 to give riders a sense of complete freedom to drivethe vehicle 360 within an open area that is actually electronicallyconstrained. Indeed, riders may be allowed to direct the vehicles 360anywhere within the grid but not outside of it.

The tracking system 10, in certain embodiments, may cause one of thevehicles 360 (e.g., via the ride control system 382) to stop. Forexample, the tracking system 10 may determine that the vehicle 360proximate the boundary line 426 between the first and fourth blocks 414,428 is too close to the first block 414 because the unoccupied vehicle416 has not yet loaded. In this scenario, the tracking system 10 maycause the vehicle 360 to stop (e.g., via ride control system 382).However, the tracking system 10 may also cause one or more show effectsto trigger so that the stop appears to be intentional (i.e., part of theride) to the people on the stopped vehicle 360. Once the tracking system10 determines that the vehicle 416 is loaded and begins moving, thetracking system 10 may also re-initiate (or re-allow) movement of thevehicle 360. Indeed, the tracking system 10 may, rather than controllingall aspects of the movement of the vehicles 360, only send “go” or“no-go” signals that allow or disallow movement as appropriate.

FIG. 27 illustrates another embodiment of the manner in which thetracking system 10 may be used to control movement of the ride vehicles360. Specifically, FIG. 27 is an elevational view of an embodiment ofthe attraction 364 in which the ride vehicle 360 is guided along aguidance path 440, which may be considered to represent a more specificembodiment of the unconstrained path 363. The guidance path 440, asillustrated, includes a plurality of the retro-reflective markers 24 ina funnel-like pattern 442, which may ultimately function to cause theride vehicle 360 to be guided along a particular trajectory along thepath 440 and toward a predetermined location 444.

More specifically, the illustrated pattern 442 is formed by a firstplurality of retro-reflective markers 446 positioned at a first side 448of the path 440, and a second plurality of retro-reflective markers 450positioned at a second side 452 of the path 440. The first and secondpluralities of retro-reflective markers 446, 450 are spaced apart by adistance that changes along a direction extending toward thepredetermined location 444. As illustrated toward the left side of thepath 440, the distance is depicted as W1, representing a first width,and, moving to the right and toward the predetermined location 444, thewidth changes to a second width W2, which is smaller than the firstwidth W1. In this way, the converging pluralities of retro-reflectivemarkers 446, 450 define a tapered space 454 where no retro-reflectivemarkers 24 are present. As described in further detail below, thetracking system 10 and the ride control system 382 may operate toconstrain the ride vehicle 360 to within this tapered space 454.

As also illustrated, the ride vehicle 360 may include various featuresthat enable the person 70 within the ride vehicle 360 to move the ridevehicle 360 in a number of different directions. Generally, thesefeatures of the ride vehicle 360 function to allow the person 70 to feelas if they are in full control over the ride vehicle 360 while thevehicle 360, in reality, is being directed in the general directiontoward the predetermined location 444. The features include, by way ofexample, a vehicle drive system 456 that may be in communication withthe tracking system 10 and/or the ride control system 382 via thetransceiver 404.

The vehicle drive system 456 generally includes a drive system 458 and asteering system 460, which are configured to move the vehicle 360 alongthe path 440 and also allow the person 70 a degree of control over themovement of the vehicle 360. The drive system 458 may include one ormore electromechanical drives (e.g., electric motors) and associatedpower systems, one or more combustion engines, one or more propulsiondevices, and so forth. The steering system 460 may include any suitableset of features that enable the vehicle 360 to be steered, such as, forinstance, a rack and pinion system, steering column, etc.

As set forth above, the tracking system 10 and the ride control system382 may operate in conjunction with the vehicle drive system 456 toadjust the degree of control that the person 70 driving the ride vehicle360 has over the overall direction in which the ride vehicle 360travels. For example, the tracking system 10 may track the location andmovement of the ride vehicle 360 and send this tracking information tothe ride control system 382. Alternatively, the tracking system 10 mayprocess the tracking data to provide an instruction input to the ridecontrol system 382.

As an example of the manner in which the amusement attraction 364functions, the ride vehicle 360 may travel along the path 440, whilebeing tracked by the tracking system 10 using any one or a combinationof the techniques described above. The tracking system 10 may also, forexample, treat the first and second pluralities of retro-reflectivemarkers 446, 450 as boundary features, where the tracking system 10monitors the location of the vehicle 360 relative to the first andsecond pluralities of retro-reflective markers 446, 450, and determineswhether the vehicle 360 has encroached into either of the pluralities ormay, based upon a determined trajectory, encroach into either of thepluralities.

If the tracking system 10 determines that the vehicle 360 requiresadjustment (e.g., according to a stored set of instructions or rulesassociated with the attraction 364), the tracking system 10 may sendappropriate instructions to the ride control system 382 to cause thevector orientation or magnitude of the vehicle's movement to beadjusted. In accordance with the illustrated embodiment, the adjustmentmay be made so that the vehicle 360 is urged in a direction toward thepredetermined location 444. Accordingly, while the person 70 may believethat they are in complete control over the vehicle 360, they are slowlybeing urged toward the location 444.

The amusement attraction 364 may also include amusement park equipment12 to create show reasons for the vehicle 360 to move along the path 440toward the location 444. For example, as shown, the person 70 may, uponidentification of the amusement park equipment 12 such as a show effect(e.g., a flame, a display), steer the ride vehicle 360 toward theequipment 12. In doing so, the person 70 causes the vehicle 360 to bedirected further into the tapered area 454, and therefore directedcloser to the location 444.

Further embodiments of the path 440 are depicted in the overhead viewsof FIGS. 28 and 29. Specifically, in FIG. 28, the path 440 may beconsidered to be an overhead view of the path 440 in FIG. 27, wheremovement of the vehicle 360 is constrained to within the tapered area454 where retro-reflective markers 24 are not present. As also shown inFIG. 28, the tracking system 10 may utilize multiple emitters 14 anddetectors 16 to enable the control unit 18 to determine vectororientation of the vehicle 360 through the path 440 and also to providerange.

As illustrated in FIG. 29, in certain embodiments, layers of differentretro-reflective markers 24 may be used. Specifically, FIG. 29illustrates an embodiment of the guide path 440 in which the firstplurality of markers 446 and the second plurality of markers 450 eachinclude a first subset of retro-reflective markers 464 and a secondsubset of retro-reflective markers 466 that include differentretro-reflective elements or retro-reflect different wavelengths. Thefirst subset of retro-reflective markers 464 may and the second subsetof retro-reflective markers 466 are positioned at different lateralpositions relative to the guide path 440, and may be considered to serveas layers used to encourage motion of the ride vehicles 360 along thepath 440 toward the predetermined location 444 in distinct ways, eventhough riders in the vehicles 360 may believe that the vehicles cantravel outside of the path 440, as generally depicted by arrows 470.

For example, as shown with respect to the first ride vehicle 360A, thetracking system 10 may detect that the first ride vehicle 360A hasoccluded a portion of the first subset of retro-reflective markers 464,and may initiate a first response in the first vehicle 360A, such assputtering of the first vehicle 360A, slowing of the first vehicle 360A,or some other haptic feedback that encourages the riders to direct thefirst vehicle 360A back into the path 440. In situations where theriders continue to direct vehicles 360 outside of the path 440, asillustrated with respect to the second ride vehicle 360B, the trackingsystem 10 may detect that the second ride vehicle 360B has occluded aportion of the second subset of retro-reflective markers 466, and mayinitiate a second response in the second vehicle 360B, that is moresevere than the first response, such as stopping the second vehicle360B, turning the second vehicle 360B, or some other control that movesthe second vehicle 360B back into the path 440.

FIG. 30 depicts an embodiment of the guide path 440 where, rather thanconstraining the vehicle to a tapered area in which retro-reflectivemarkers are not present as in FIGS. 27-29, the amusement attraction 364instead uses the tracking system 10 to ensure that the vehicle 360remains over a grid path 480 established by a particular pattern ofretro-reflective markers 24. The retro-reflective markers 24, as shown,are formed into a tapered pattern such that to remain over at least someof the markers 24, the vehicle 360 must travel generally along apredetermined trajectory 482, and not along a trajectory 484 that causesthe vehicle 360 to stop occluding at least some of the markers 24. Totaper the path 440 in a similar manner as set forth above with respectto FIGS. 27 and 28, the grid path 480 tapers from the first width W1 andto the second width W2. The tracking system 10, accordingly, may monitorgrid occlusion to determine vector magnitude, orientation, and senseinformation relating to the movement of the vehicle 360, and may makecertain adjustments to these or other parameters (e.g., using the ridecontrol system 382) if the tracking system 10 determines that thevehicle 360 has or is likely to move off of the grid path 480.

While only certain features of the present embodiments have beenillustrated and described herein, many modifications and changes willoccur to those skilled in the art. It is, therefore, to be understoodthat the appended claims are intended to cover all such modificationsand changes as fall within the true spirit of the invention.

The invention claimed is:
 1. An amusement park ride system, comprising:a ride vehicle positioned on a ride path and configured to move alongthe ride path; a plurality of retro-reflective markers positioned on theride vehicle, along the ride path, or both; an emission subsystemconfigured to emit electromagnetic radiation toward the plurality ofretro-reflective markers; a detection subsystem configured to detect apattern of retro-reflection of the electromagnetic radiation from theplurality of retro-reflective markers while filtering electromagneticradiation that is not retro-reflected; and a control systemcommunicatively coupled to the detection subsystem and comprisingprocessing circuitry configured to: monitor the pattern ofretro-reflection of the electromagnetic radiation from the plurality ofretro-reflective markers for changes; and track movement of the ridevehicle in space and time based on changes in the pattern ofretro-reflected electromagnetic radiation detected by the detectionsubsystem.
 2. The system of claim 1, wherein the detection subsystemcomprises at least one detection camera having at least one opticalfilter and an overhead view of the ride path, wherein the at least oneoptical filter is configured to filter electromagnetic radiation that isnot retro-reflected while not filtering electromagnetic radiation thatis retro-reflected by the plurality of retro-reflective markers.
 3. Thesystem of claim 1, wherein the ride path comprises a rail system, andthe plurality of retro-reflective markers comprises retro-reflectivemarkers positioned on the rail system wherein the processing circuitryof the control system is configured to monitor retro-reflectedelectromagnetic radiation from the retro-reflective markers on the trackfor a change from a first pattern of retro-reflected electromagneticradiation to a second pattern of retro-reflected electromagneticradiation.
 4. The system of claim 3, wherein the processing circuitry ofthe control system is configured to: correlate portions of the firstpattern no longer present in the second pattern with a pattern ofretro-reflective markers on the track occluded by the ride vehicle overtime; and determine a vector orientation of the movement of the ridevehicle on the track based on the pattern of retro-reflective markers onthe track occluded by the ride vehicle.
 5. The system of claim 4,wherein the processing circuitry is configured to maintain apredetermined relationship between the vector orientation and the track.6. The system of claim 3, wherein the processing circuitry of thecontrol system is configured to: correlate portions of the first patternno longer present in the second pattern with a pattern ofretro-reflective markers on the track occluded by the ride vehicle;compare the pattern of retro-reflective markers on the track occluded bythe ride vehicle with a stored geometry of the ride vehicle; andidentify whether the stored geometry of the ride vehicle and the patternof retro-reflective markers on the track occluded by the ride vehiclehave a predetermined geometric relationship.
 7. The system of claim 6,wherein the processing circuitry of the control system is configured tocontrol at least one operating parameter of the ride vehicle to maintainthe predetermined geometric relationship.
 8. The system of claim 1,comprising an effect device positioned along the track and incommunication with the control system, and wherein the processingcircuitry of the control system is configured to determine, based on thetracked location and movement of the ride vehicle and a stored locationof the effect device, a location of the ride vehicle relative to theeffect device, and wherein the processing circuitry of the controlsystem is configured to trigger the effect device when the location ofthe ride vehicle is within a predetermined distance to the effectdevice.
 9. The system of claim 1, wherein: the plurality ofretro-reflective markers comprises a set of retro-reflective markerspositioned on the path in a predetermined relationship relative to adirection of intended travel of the ride vehicle, the direction ofintended travel being oriented toward a predetermined location along thepath; the ride vehicle comprises communication circuitry configured tocommunicate with the control system and a drive system configured toenable steering and velocity control of the ride vehicle; and theprocessing circuitry of the control system is configured to maintain theride vehicle generally along the direction of intended travel, overtime, based on monitored retro-reflection from the retro-reflectivemarkers on the path.
 10. The system of claim 9, wherein the plurality ofretro-reflective markers comprises a first set of retro-reflectivemarkers positioned on a first side of the path and a second set ofretro-reflective markers positioned on a second side of the path, thefirst and second sides of the path being at opposite lateral extents ofthe path relative to the direction of intended travel of the ridevehicle, and wherein the processing circuitry is configured to: identifyocclusion of retro-reflective markers of the first set ofretro-reflective markers or second set of retro-reflective markers, orboth, based on a change from a first pattern of retro-reflectedelectromagnetic radiation to a second pattern of retro-reflectedelectromagnetic radiation in which a portion of the first pattern is nolonger present; correlate the occlusion of the retro-reflective markerswith the presence of the ride vehicle; and adjust a movement vector ofthe ride vehicle to return the ride vehicle to a region of the pathbetween the first and second sets of retro-reflective markers using thedrive system of the ride vehicle.
 11. The system of claim 10, whereinthe first and second sets of retro-reflective markers converge towardone another such that the region of the path between the first andsecond sets of retro-reflective markers tapers toward the predeterminedlocation.
 12. The system of claim 9, wherein the plurality ofretro-reflective markers comprises a set of retro-reflective markerspositioned along the direction of intended travel of the ride vehicleand in a tapered geometry, and wherein the tapered geometry of the setof retro-reflective markers tapers toward the predetermined location.13. The system of claim 1, wherein the processing circuitry isconfigured to: identify occlusion of retro-reflective markers of the setof retro-reflective markers based on a change from a first pattern ofretro-reflected electromagnetic radiation to a second pattern ofretro-reflected electromagnetic radiation in which a portion of thefirst pattern is no longer present; correlate the occlusion of theretro-reflective markers with the presence of the ride vehicle; andmaintain occlusion of at least a portion of the set of retro-reflectivemarkers by the ride vehicle using the drive system of the ride vehicleto maintain a vector orientation of the movement of the ride vehiclegenerally along the direction of intended travel.
 14. The system ofclaim 1, wherein the plurality of retro-reflective markers comprises atleast three retro-reflective markers positioned on different sides ofthe ride vehicle, and wherein the detection subsystem comprises at leasttwo detector cameras configured to detect retro-reflectedelectromagnetic radiation from the at least three retro-reflectivemarkers while filtering out electromagnetic radiation that is notretro-reflected, and wherein the processing circuitry of the controlsystem is configured to track the ride vehicle in space and time inthree spatial dimensions based on the retro-reflected electromagneticradiation from the at least three retro-reflective markers.
 15. Thesystem of claim 14, wherein the processing circuitry of the controlsystem is configured to track the ride vehicle in space and time in thethree spatial dimensions relative to the path.
 16. A method of trackingand controlling an amusement park ride vehicle, comprising: flooding aride vehicle path of an amusement park attraction with electromagneticradiation using an emission subsystem comprising one or more emitters;detecting wavelengths of electromagnetic radiation retro-reflected fromwithin the ride vehicle path while filtering wavelengths ofelectromagnetic radiation not retro-reflected from within the guestattraction area using a detection subsystem having one or more opticalfilters; and tracking, in space and time, a movement and a location of aride vehicle on the ride vehicle path based on changes in theretro-reflected electromagnetic radiation with a control systemcommunicatively coupled to the detection subsystem.
 17. The method ofclaim 16, comprising controlling at least one operating parameter of theride vehicle based on the tracked movement and location of the ridevehicle on the ride vehicle path using the control system, whereintracking, in space and time, the movement and the location of the ridevehicle on the ride vehicle path comprises: tracking patterns ofretro-reflected electromagnetic radiation produced from retro-reflectionby the retro-reflective markers positioned on the ride vehicle path;identifying changes in the patterns of retro-reflected electromagneticradiation in which a first pattern of retro-reflected electromagneticradiation changes to a second pattern of retro-reflected electromagneticradiation in which portions of the first pattern of retro-reflectedelectromagnetic radiation are no longer present; and correlating theportions of the first pattern of retro-reflected electromagneticradiation no longer present in the second pattern with occlusion ofretro-reflective markers positioned on the ride vehicle path by the ridevehicle; and wherein controlling at least one operating parameter of theride vehicle based on the tracked movement and location of the ridevehicle on the ride vehicle path using the control system comprisescontrolling the at least one operating parameter to maintain apredetermined degree of occlusion of the retro-reflective markers on thepath by the ride vehicle.
 18. The method of claim 16, comprising:retro-reflecting the electromagnetic radiation using at least threeretro-reflective markers positioned on different sides of the ridevehicle; detecting, from different perspectives, retro-reflectedelectromagnetic radiation from the at least three retro-reflectivemarkers while filtering out electromagnetic radiation that is notretro-reflected using at least two detector cameras of the detectionsubsystem; and tracking the ride vehicle in space and time in threespatial dimensions based on the retro-reflected electromagneticradiation from the at least three retro-reflective markers using thecontrol system.
 19. The method of claim 16, comprising triggering aneffect device when the tracked location and movement of the ride vehicleindicates that the ride vehicle is within a predetermined distance ofthe effect device.